Antibodies against SARS-CoV-2 and methods of using the same

ABSTRACT

The instant disclosure provides antibodies and antigen-binding fragments thereof that can bind to a SARS-CoV-2 antigen and, in certain embodiments, are capable of neutralizing a SARS-CoV-2 infection. Also provided are polynucleotides that encode an antibody or antigen-binding fragment, vectors and host cells that comprise a polynucleotide, pharmaceutical compositions, and methods of using the presently disclosed antibodies, antigen-binding fragments, polynucleotides, vectors, host cells, and compositions to treat or diagnose a SARS-CoV-2 infection.

STATEMENT REGARDING SEQUENCE LISTING

The Sequence Listing associated with this application is provided in text format in lieu of a paper copy, and is hereby incorporated by reference into the specification. The name of the text file containing the Sequence Listing is 930585_402_SEQUENCE_LISTING.txt. The text file is 328 KB, was created on Apr. 21, 2021, and is being submitted electronically via EFS-Web.

BACKGROUND

A novel betacoronavirus emerged in Wuhan, China, in late 2019. As of Feb. 19, 2021, approximately 110 million cases of infection by this virus (termed, among other names, SARS-CoV-2 and originally identified as Wuhan coronavirus), were confirmed worldwide, and had resulted in approximately 2.45 million deaths. Modalities for preventing or treating SARS-CoV-2 infection, and diagnostic tools for diagnosing a SARS-CoV-2 infection, are needed.

BRIEF DESCRIPTION OF THE DRAWINGS

FIGS. 1A and 1B show binding by antibodies (1A) S303 (VH SEQ ID NO.:63; VL SEQ ID NO.:67) and (1B) S309 (VH SEQ ID NO.:105; VL SEQ ID NO.:168) of the present disclosure to recombinant SARS-CoV-2 RBD, as described in Example 2.

FIGS. 2A and 2B show SARS-CoV-2 neutralization of infection by certain antibodies of the present disclosure, as described in Example 4.

FIGS. 3A-3I show SARS-CoV-2 neutralization of infection, as described in Example 4. FIG. 3A shows neutralization by donor plasma from SARS-CoV-1 survivors. FIGS. 3B-3D and 3I show neutralization by supernatant from B cells expressing certain antibodies of the present disclosure. FIGS. 3E-3H show neutralization by certain recombinant IgG1 antibodies.

FIGS. 4A and 4B show binding of antibody-containing B cell supernatant to SARS-CoV-2 S protein expressed on ExpiCHO cells, as described in Example 1. Graphs showing binding profiles of antibodies S300-S310 are indicated with boxes.

FIGS. 5A and 5B show binding of antibodies S311 and S312 in the supernatant of cultured B cells to SARS-CoV-1 and SARS-CoV-2, as described in Example 6. Antibody concentrations are estimates. SARS Si Sino: protein from Sino Biological. RBD2: RBD of SARS-CoV-2 produced in-house.

FIGS. 6A-6E show (top) binding curves of certain antibodies of the present disclosure for SARS-CoV-1 (SARS1) RBD and SARS-CoV-2 (SARS2) RBD, as measured by Octet, and (bottom) KD values. KD values for antibodies (e.g., <1.0×10⁻¹² M) with very strong binding and slow dissociation are estimates. These data and experiments are described further in Example 3.

FIG. 7 shows neutralization of infection by S304 (VH SEQ ID NO.:79; VL SEQ ID NO.:83) and S309 (VH SEQ ID NO.:105; VL SEQ ID NO.:168) antibodies, alone or in combination, against SARS-CoV-2 pseudotyped virus, as described in Example 5.

FIGS. 8A-8K show binding curves of certain antibodies for RBD of SARS-CoV-1, RBD of SARS-CoV-2, and ectodomains of various coronaviruses, as measured by ELISA. See Example 8.

FIG. 9 shows neutralization of infection by S309 rIgG1 (VH SEQ ID NO.:105; VL SEQ ID NO.:168) and S315 rIgG1 (VH SEQ ID NO.:178; VL SEQ ID NO.:182) against SARS-CoV-2 pseudotyped virus, as described in Example 7.

FIG. 10 shows neutralization of infection by S309 full-length rIgG1 and S309 rFab (both of which comprise a VH of SEQ ID NO.:105 and a VL of SEQ ID NO.:168) against SARS-CoV-2 pseudotyped virus, as described in Example 7.

FIG. 11 shows binding of antibody S309 (VH SEQ ID NO.:105; VL SEQ ID NO.:168) to SARS-CoV-1 and SARS-CoV-2 spike protein expressed on ExpiCHO cells, as described in Example 9. Stacked histograms of flow cytometry graphs show antibody dose-dependent binding of S309 to SARS-CoV and SARS-CoV-2.

FIGS. 12A and 12B show concentration-dependent binding measured by flow cytometry for certain antibodies, as described in Example 9. FIG. 12A shows binding to SARS-CoV-2. FIG. 12B shows binding to SARS-CoV-1.

FIG. 13 shows neutralization of infection by antibodies S303 (VH SEQ ID NO.:63; VL SEQ ID NO:67), S304 (VH SEQ ID NO.:79; VL SEQ ID NO.:83), S306 (VH SEQ ID NO.:87; VL SEQ ID NO.:91), S309 (VH SEQ ID NO.:105; VL SEQ ID NO.:168), S310 (VH SEQ ID NO.:155; VL SEQ ID NO.:159), and S315 (VH SEQ ID NO.:178; VL SEQ ID NO.:182) against SARS-CoV-2 pseudotyped virus, as described in Example 4.

FIGS. 14A-14D show binding affinity/avidity of antibodies S309 (VH SEQ ID NO.:105; VL SEQ ID NO.:168), S303 (VH SEQ ID NO.:63; VL SEQ ID NO:67), S304 (VH SEQ ID NO.:79; VL SEQ ID NO.:83), and S315 (VH SEQ ID NO.:178; VL SEQ ID NO.:182) to RBD of SARS-CoV-1 (right panels) and SARS-CoV-2 (left panels), as described in Example 10.

FIGS. 15A and 15B show competition of pairs of antibodies of the present disclosure for binding to the RBD of SARS-CoV-1 (FIG. 15A) and SARS-CoV-2 (FIG. 15B), as described in Example 12. For each graph, the x-axis shows time (0 to 1000 seconds), and the y-axis shows the binding to RBD as measured by BLI (0 to 3 nm). The first antibody is indicated on the left of the matrix and the second antibody is indicated on the top of the matrix. The dashed vertical lines in FIG. 15B show the switch from the first antibody to the second antibody. At right (“I”-“IV” in FIG. 15A, “II” and “IV” in FIG. 15B) are antigenic sites as determined by structural information, escape mutant analysis, and BLI-based epitope binning.

FIG. 16 shows the ability of S309 to interfere with RBD of SARS-CoV-1 (left) or SARS-CoV-2 (right) binding to human ACE2 (hACE2), as described in Example 13. hACE2 was loaded onto BLI sensors, followed by incubation of the sensors with RBD alone or RBD in combination with antibody. The vertical dashed line indicates the start of the association of RBD with or without antibody. In the graph at left, antibody S230 was used as a positive control of inhibition of SARS-CoV-1 RBD binding to ACE2 based on previous studies (see. Walls et al., Cell 176(5):1023-1039.e15 (2019)).

FIGS. 17A and 17B show antibody-dependent effects of certain antibodies of the present disclosure against model infected cells, as described in Example 14. FIG. 17A shows antibody-dependent cytotoxicity using primary NK effector cells and SARS-CoV-2-expressing ExpiCHO cells as target cells. Bar graph at right shows ADCC for the indicated antibody(ies), calculated as area under the curve (AUC).

FIG. 17B shows antibody-dependent cellular phagocytosis using PBMCs as phagocytic cells and PKF67-labelled SARS-CoV-2-expressing ExpiCHO as target cells. Line graphs show mean fluorescence intensity (MFI) of PBMCs after incubation with target cells and antibodies, determined for one representative donor with high affinity FcγRIIIa (symbols show means±SD of duplicates).

FIGS. 18A-18J show binding curves of certain recombinant antibodies for RBD of SARS-CoV-1, RBD of SARS-CoV-2, and ectodomains of various coronavirus strains, as measured by ELISA. See Example 8. Recombinant mAbs were tested by ELISA at a concentration range of 5 to 0.00028 mg/ml. RBD2: Receptor binding domain of SARS-CoV-2. RBD1: Receptor binding domain of SARS-CoV (also referred-to herein as SARS-CoV-1). Spike: stabilized prefusion trimer of the indicated coronavirus. Some antibodies were recombinantly expressed as IgG1 (rIgG1), and some antibodies were recombinantly expressed as IgG1 with the MLNS mutation (M428L and N434S (EU numbering)) in the Fc (rIgG1-LS).

FIGS. 19A and 19B show ability of certain antibodies to interfere with RBD binding to human ACE2, as described in Example 13. Human ACE2 (hACE2) was loaded onto BLI sensors, followed by incubation of the sensors with RBD alone or RBD in combination with recombinant antibody. The vertical dashed line indicates the start of the loading of RBD with or without antibody. RBD: Receptor binding domain. FIG. 19A shows SARS-CoV-1 RBD binding to ACE2. FIG. 19B shows SARS-CoV-2 RBD binding to ACE2.

FIGS. 20A and 20B show binding affinity and avidity of antibody S309 IgG (FIG. 20A) versus S309 Fab (FIG. 20B) for SARS-CoV-1 RBD (bottom of each figure) and SARS-CoV-2 RBD (top of each figure), as described in Example 10. For both the IgG and the Fab: VH SEQ ID NO.:105; VL SEQ ID NO.:168. RBD was loaded to BLI pins and association of different concentrations of S309-IgG-MLNS or S309 Fab was measured. Vertical dashed lines indicate the start of the dissociation phase when BLI pins were switched to buffer.

FIG. 21A-21C show reactivity of S304 (VH SEQ ID NO.:79; VL SEQ ID NO.:83), S306 (VH SEQ ID NO.:87; VL SEQ ID NO.:91), S309 (VH SEQ ID NO.:105; VL SEQ ID NO.:168), and S310 (VH SEQ ID NO.:155; VL SEQ ID NO.:159) antibodies against SARS-CoV-2, as described in Example 15. FIG. 21A shows reactivity of S304, S306, S309, and S310 antibodies against TX100 extracted lysate of SARS-CoV-2 infected Vero E6 cells. FIG. 21B shows reactivity of the same antibodies against SDS extracted lysate of SARS-CoV-2 infected Vero E6 cells. FIG. 21C shows reactivity of human SARS-CoV-1 convalescent serum against TX100 extracted or SDS extracted lysate of SARS-CoV-2 infected Vero E6 cells. FIGS. 21A and 21B also show data for comparator antibody LCA57, which is specific for spike protein of MERS-CoV (Corti et al. PNAS 112(33):10473-10478 (2015).

FIG. 22A-22D show neutralization of SARS-CoV-2 infection by antibodies as assessed by inhibition of nucleoprotein (NP) expression at 24 and 45 hours post infection. See Example 16. FIG. 22A shows neutralization of SARS-CoV-2 infection by S304 S304 (VH SEQ ID NO.:79; VL SEQ ID NO.:83). FIG. 22B shows neutralization of SARS-CoV-2 infection by S309 (VH SEQ ID NO.:105; VL SEQ ID NO.:168. FIG. 22C shows neutralization of SARS-CoV-2 infection by the combination of S304 and S309. FIG. 22D shows control neutralization of SARS-CoV-2 infection by comparator antibody LCA57, which is specific for spike protein of MERS-CoV (Corti et al. PNAS 112(33):10473-10478 (2015)).

FIG. 23 shows neutralization of infection by antibodies S309 (VH SEQ ID NO.:105; VL SEQ ID NO.:168) and S315 (VH SEQ ID NO.:178; VL SEQ ID NO.:182), alone or in combination, against SARS-CoV-2 pseudotyped virus, as described in Example 5.

FIGS. 24A and 24B show antibody-dependent effects of certain antibodies of the present disclosure against model infected cells, as described in Example 14. FIG. 24A shows antibody-dependent cell-mediated cytotoxicity (ADCC) using primary NK effector cells and SARS-CoV-2-expressing ExpiCHO cells as target cells. The graph shows the % killing of target cells after incubation with antibody or combination of antibodies shown in the legend. FIG. 24B shows ADCC for the indicated antibody(ies), calculated as area under the curve (AUC). Left panel: AUC determined using cells with VV FcγRIIIa genotype; right panel: AUC determined for cells with FF or FV FcγRIIIa genotype.

FIGS. 25A and 25B show further antibody-dependent effects of certain antibodies of the present disclosure, as described in Example 14. FIG. 25A shows antibody-dependent cellular phagocytosis (ADCP) using PBMCs as phagocytic cells and PKF67-labelled SARS-CoV-2-expressing ExpiCHO cells as target cells. The graph shows mean fluorescence intensity (MFI) of PBMCs after incubation with target cells and antibodies, determined for one representative donor with high affinity FcγRIIIa (symbols show means±SD of duplicates). FIG. 25B shows ADCP for the indicated antibody(ies), calculated as area under the curve (AUC).

FIG. 26 shows antibody binding as measured by flow cytometry. Binding of antibody S309 to SARS-CoV-2 Spike protein expressed in Expi-CHO cells was detected with a fluorescently labeled secondary antibody.

FIG. 27 shows binding of antibody S309 (labeled as “11” in the figure key) and four engineered variants of S309 (labeled as “12” through “15”, respectively) to S protein, as measured by flow cytometry. See Example 9. The four engineered variant antibodies are as follows: S309 N55Q comprises an N55Q mutation in CDRH2, resulting in a variant VH sequence (SEQ ID NO:.113), and the wild-type VL sequence (SEQ ID NO.:168) of S309; S309 W50F comprises a W50F variant VH sequence (SEQ ID NO: 129) and the wild-type VL sequence (SEQ ID NO.:168) of S309; S309 W105F comprises a W105F variant VH sequence (SEQ ID NO: 119) and the wild-type VL sequence (SEQ ID NO.:168) of S309; and S309 W50F/G56A/W105F comprises a W50F/G56A/W105F variant VH sequence (SEQ ID NO.:172) and the wild-type VL sequence of S309. In FIG. 27, S309 N55Q is labeled as “12,” S309 W50F is labeled as “13,” S309 W105F is labeled as “14,” and S309 W50F-G56A-W105F is labeled as “15.” Antibody binding to SARS-CoV-2 Spike protein expressed on Expi-CHO cells was detected with a fluorescently labeled secondary antibody. Data from two experiments are shown.

FIG. 28 shows neutralization of infection by antibody S309 (referred to in the figure as “Variant-11 (wt)”) and four S309 variant antibodies against SARS-CoV-2 pseudotyped viruses, as described in Example 19. In FIG. 28, S309 N55Q is labeled as “Variant-12,” S309 W50F is labeled as “Variant-13,” S309 W105F is labeled as “Variant-14,” and S309 W50E-G56A-W105F is labeled as “Variant-15.” Pseudotyped viruses are VSV pseudotyped with SARS-CoV-2 Spike protein.

FIG. 29 shows a summary of results from binding and pseudovirus neutralization assays for antibody S309 (“S309-WT”) and four engineered variants of S309 (“N55Q”; “W50F”; “W105F”; “W50F/G56A/W105F”). The dashed horizontal line shows change of function of engineered variant versus S309-WT baseline. Differently hatched bars show binding to glycosylated RBD as measured by SPR, binding to deglycosylated RBD as measured by SPR, binding to antigen-expressing cells, as measured by FACS, and neutralization as measured using SARS-CoV-2 pseudoviruses.

FIGS. 30A-30F show binding kinetics of exemplary antibodies to SARS-CoV-2 glycosylated or deglycosylated RBD as measured by SPR. See Example 18. Antibodies S309 (having S309 wild-type VH (SEQ ID NO.:105) and VL (SEQ ID NO.: 168) amino acid sequences), S309 N55Q, S309 W50F, S309 W105F, and S309 W50F/G56A/W105F were tested. FIG. 30A shows binding kinetics of S309 wild type antibody (2 replicate experiments). FIG. 30B shows binding kinetics of S309 N55Q (bottom), as compared to S309 wild type antibody (top). FIG. 30C shows binding kinetics of S309 W50F (bottom) as compared to S309 wild type antibody (top). FIG. 30D shows binding kinetics of S309 W105F (bottom) as compared to S309 wild type antibody (top). FIG. 30E shows binding of S309 W50F/G56A/W105F (bottom) as compared to S309 wild type antibody (top). FIG. 30F shows binding of S309 W50F/G56A/W105F using 10 minute injection period (top panel) or 3 minute injection period (bottom panel).

FIG. 31 shows activation of high affinity (158V) FcγRIIIa (left panel) or low affinity (158F) FcγRIIIa (right panel) by antibodies S303 (VH SEQ ID NO.:63; VL SEQ ID NO:67), S304 (VH SEQ ID NO.:79; VL SEQ ID NO.:83), S306 (VH SEQ ID NO.:87; VL SEQ ID NO.:91), S309 (VH SEQ ID NO.:105; VL SEQ ID NO.:168), and a combination of S309 and S315, along with comparator antibody S230. See Example 20. Activation was measured using SARS-CoV-2 S-expressing ExpiCHO cells as target cells and Jurkat reporter cells stably transfected with NFAT-driven luciferase reporter gene. Activation of FcγRIIIa results in NFAT-mediated expression of the luciferase reporter gene. Results are from one experiment, one or two measurements per mAb.

FIG. 32 shows activation of FcγRIIa by exemplary antibodies S303 (VH SEQ ID NO.:63; VL SEQ ID NO.:67), S304 (VH SEQ ID NO.:79; VL SEQ ID NO.:83), S306 (VH SEQ ID NO.:87; VL SEQ ID NO.:91), S309 (VH SEQ ID NO.:105; VL SEQ ID NO.:168), and a combination of S309 and S315, along with comparator monoclonal antibody S230. See Example 20. Activation was measured using SARS-CoV-2 S-expressing ExpiCHO cells as target cells and Jurkat reporter cells stably transfected with NFAT-driven luciferase reporter gene. Activation of FcγRIIa results in NFAT-mediated expression of the luciferase reporter gene.

FIGS. 33A and 33B show binding of antibodies S303 (VH SEQ ID NO.:63; VL SEQ ID NO:67), S304 (VH SEQ ID NO.:79; VL SEQ ID NO.:83), S306 (VH SEQ ID NO.:87; VL SEQ ID NO.:91), S309 (VH SEQ ID NO.:105; VL SEQ ID NO.:168), S310 (VH SEQ ID NO.:155; VL SEQ ID NO.:159), and S315 (VH SEQ ID NO.:178; VL SEQ ID NO.:182), along with comparator antibodies S110, S230, and S109, to S protein expressed on a cell surface. See Example 9. FIG. 33A shows binding to ExpiCHO cells transfected with SARS-CoV-2 S protein. FIG. 33B shows binding to ExpiCHO cells transfected with SARS-CoV-1 S protein. Mean fluorescence intensity was measured by flow cytometry for each antibody. Antibody concentrations tested are indicated in the x-axis.

FIG. 34 shows neutralization of infection by exemplary antibodies S303 (VH SEQ ID NO.:63; VL SEQ ID NO:67), S304 (VH SEQ ID NO.:79; VL SEQ ID NO.:83), S306 (VH SEQ ID NO.:87; VL SEQ ID NO.:91), S309 (VH SEQ ID NO.:105; VL SEQ ID NO.:168), S310 (VH SEQ ID NO.:155; VL SEQ ID NO.:159), and S315 (VH SEQ ID NO.:178; VL SEQ ID NO.:182) against SARS-CoV-1 pseudotyped virus. See Example 4.

FIGS. 35A and 35B show conservation of Spike protein residues, as described in Example 21. FIG. 35A shows Spike protein variants occurring with a frequency of n>1 as spheres mapped onto the closed (left) and open (right) form of the full trimeric Spike ectodomain. The RBD and other Spike protein domains are shown as indicated. 40 mutations (out of 2229 total) are shown. Only residue 367 (n=8) is highlighted in the RBD, and residues 476 (n=7) and 483 (n=17) are not. FIG. 35B shows the prevalence of variants in Spike glycoprotein by amino acid. Each dot is a distinct variant. The locations of Domain A and RBD are shown. Variants passing a frequency threshold of 0.1% are as indicated.

FIG. 36 shows neutralization of SARS-CoV-2-MLV by antibody S309 (VH SEQ ID NO.:105; VL SEQ ID NO.:168) combined with an equimolar amount of antibody S304 (VH SEQ ID NO.:79; VL SEQ ID NO.:83). For antibody cocktails, the concentration shown on the x axis is that of the individual antibodies. See Example 4.

FIG. 37 shows neutralization of SARS-CoV2-MLV by S309 (VH SEQ ID NO.:105; VL SEQ ID NO.:168) combined with an equimolar amount of antibody S315 (VH SEQ ID NO.:178; VL SEQ ID NO.:182) antibodies. For antibody cocktails, the concentration shown on the x axis is that of the individual antibodies. See Example 4.

FIGS. 38A-38D show binding of certain antibodies to RBD of SARS-CoV-2 and SARS-CoV-1, as described in Example 6. Antibodies were expressed recombinantly and binding was assayed using ELISA. 96-well ELISA plates were coated with SARS-CoV-2 RBD (produced in house; residues 331-550 of Spike protein from BetaCoV/Wuhan-Hu-1/2019, accession number MN908947) at 10 μg/ml and SARS-CoV-1 RBD (Sino Biological, 40150-V08B1) at 1 μg/ml. After blocking with 1% BSA in PBS, antibodies were added to the plates and incubated at room temperature for one hour. Plates were washed and secondary antibody goat anti-human IgG-AP (Southern Biotechnology, 2040-04) was added. Substrate p-nitrophynylphosphate (pNPP, Sigma-Aldrich, 337 71768) was used for color development. OD405 was analyzed on an ELx808IU plate reader (Biotek). Left panel of each figure shows binding to SARS-CoV-2 RBD and right panel shows binding to SARS-CoV-1 RBD.

FIGS. 39A and 39B show binding of certain antibodies to Spike protein of SARS-CoV-2 and SARS-CoV-1, as described in Example 9. Expi-CHO cells were transiently transfected with phCMV1-SARS-CoV-2-S, SARS-spike-pcDNA.3 (strain SARS) or empty phCMV1 using Expifectamine CHO Enhancer. Two days after transfection, cells were collected for immunostaining with antibodies. An Alexa647-labelled secondary antibody anti-human IgG Fc was used for detection. Binding of antibodies to transfected cells was analyzed by flow cytometry using a ZE5 Cell Analyzer (BioRad). FIG. 39A shows binding of recombinant antibody S300 (VH: SEQ ID NO.:1; VL: SEQ ID NO.:5). FIG. 39B shows binding of recombinant antibody S307. Symbols show the values of a single measurement. Left panel of each figure shows data presented as % positive cells and right panel shows data presented as mean fluorescent intensity (MFI).

FIGS. 40A and 40B show binding of exemplary antibodies to S glycoproteins of SARS-CoV-2 (FIG. 40A) or SARS-CoV-1 (FIG. 40B) expressed at the surface of ExpiCHO cells, as described in Example 9. Symbols are means of duplicates from one experiment.

FIGS. 41A and 41B show binding affinity and avidity of S309 IgG (FIG. 41A) and S309 Fab (FIG. 41B) for SARS-CoV-2 RBD (top panel) or SARS-CoV-2 Spike protein (bottom panel). For both IgG and Fab: VH SEQ ID NO.:105 and VL SEQ ID NO.:168. See Example 11. Biotinylated RBD of SARS-CoV-2 or biotinylated SARS-CoV-2 prefusion S ectodomain trimer were loaded onto Streptavidin biosensors, and association of different concentrations of S309-IgG-MLNS (comprising M428L and N434S Fc mutations (EU numbering)) or S309 Fab was measured. Vertical dashed lines indicate the start of the dissociation phase when biosensors were switched to buffer.

FIGS. 42A and 42B show binding of antibodies S303, S304, S306, S309, S310, and S315, along with comparator antibodies S110, S124, S230, and S109, to S protein expressed on a cell surface. See Example 9. FIG. 42A shows binding to ExpiCHO cells transfected with SARS-CoV-2 S protein. FIG. 42B shows binding to ExpiCHO cells transfected with SARS-CoV-1 S protein. Mean fluorescence intensity was measured by flow cytometry for each antibody. Antibody concentrations tested are indicated in the x axis.

FIG. 43 shows conservation of Spike protein residues, as described in Example 21. Spike protein variants supported by at least two sequences as indicated spheres mapped onto the closed (left) and open (right) form of the full trimeric Spike ectodomain. The RBD and other Spike protein domains are shown as indicated. 171 variants (out of 11,839 total Spike protein sequences analyzed) are shown.

FIGS. 44A-44C show resistance selection of SARS-CoV-2, as described in Example 23. FIG. 44A is a flow chart showing a method for resistance selection. FIG. 44B is a timeline showing the procedure used for each passage of the resistance selection process. FIG. 44C shows the results of selecting for SARS-CoV-2 resistant to antibody S309 N55Q MLNS GAALIE, comprising a VH according to SEQ ID NO.:113 and a VL according to SEQ ID NO.:168, with G236A, A330L, I332E, M428L and N434S mutations in the Fc (EU numbering).

FIG. 45 shows antibody-dependent cytotoxicity of certain antibodies of the present disclosure using primary NK cells as effector cells and SARS-CoV-2-expressing ExpiCHO cells as target cells. See Example 14. The graph shows the % killing of target cells after incubation with antibodies S309 LS (also referred to herein as S309 MLNS), S309 GRLR (G236R/L328R; non-FcR binding variant), or S309 LS GAALIE (also referred to herein as S309 MLNS GAALIE, comprising G236A, A330L, I332E, M428L, and N434S Fc mutations (EU numbering)).

FIG. 46 shows neutralization of SARS-CoV-2 infection in Calu-3 human lung cells and VeroE6 cells by antibody S309 N55Q MLNS, as described in Example 24.

FIG. 47 shows neutralization of SARS-CoV-2 infection by antibody S309 (VH SEQ ID NO.:105; VL SEQ ID NO.:168), as detected by nano luciferase assay. See Example 25. The x-axis shows antibody concentration. The three curves represent assays using three different viral concentrations in MOI (multiplicity of infection) units, as shown in the figure key at right. Data were collected six hours after infection with SARS-CoV-2 virus. Calculated IC50 values for each MOI are shown in the boxes below the graph.

FIGS. 48A and 48B show neutralization of SARS-CoV-2 infection by antibody S309 (VH SEQ ID NO.:105; VL SEQ ID NO.:168) as assayed by IFA (immunofluorescence antibody assay). See Example 25. Data were collected six hours after infection with SARS-CoV-2 virus. FIG. 48A shows photographs of representative wells, in which cell nuclei were stained blue and SARS-CoV-2 nucleocapsid were stained red, which shows up more brightly in the photographs. Each red spot in each image represents an individual infected cell. The neutralization of infection by antibody S309 can be observed as a decrease in the number of bright spots, indicating infected cells, as the concentration of S309 was increased. Antibody concentrations are shown across the top, and viral concentrations in MOI (multiplicity of infection) units are shown on the left. FIG. 48B shows quantified data from the IFA assay. Calculated IC50 values for each MOI are shown in the boxes below the graph.

FIG. 49 shows neutralization of SARS-CoV-2 infection by antibodies S309 N55Q LS (also referred to herein as S309 N55Q MLNS, comprising M428L/N434S Fc mutations (EU numbering)) and S309 N55Q LS GAALIE (also referred to herein as S309 N55Q MLNS GAALIE, comprising G236A, A330L, I332E, M428L, and N434S Fc mutations (EU numbering)). See Example 26. Each of S309 N55Q LS and S309 N55Q LS GAALIE comprises a VH having the amino acid sequence set forth in SEQ ID NO.:113 and a VL having the amino acid sequence set forth in SEQ ID NO.:168. Data represent the means of quadruplicates, +/− standard deviation. Graph shown is representative of three independent experiments.

FIGS. 50A and 50B show neutralization of infection by SARS-CoV-2 pseudotyped viruses using antibodies S309 N55Q LS (also referred to herein as S309 N55Q MLNS, comprising M428L/N434S Fc mutations (EU numbering)) (FIG. 50A) and S309 N55Q LS GAALIE (also referred to herein as S309 N55Q MLNS GAALIE, comprising G236A, A330L, I332E, M428L, and N434S Fc mutations (EU numbering)) (FIG. 50B). See Example 27. Pseudotyped viruses are VSV pseudotyped with SARS-CoV-2 Spike protein. Data represent the means of duplicates, +/− standard deviation. Each graph shown is representative of four independent experiments.

FIGS. 51A and 51B show binding of antibodies S309 N55Q MLNS (FIG. 51A) and S309 N55Q MLNS GAALIE (FIG. 51B) to SARS-CoV-2 RBD, as measured by surface plasmon resonance (SPR). See Example 28. Values are from two independent experiments.

FIGS. 52A and 52B show binding of antibodies S309 N55Q LS (also referred to herein as S309 N55Q MLNS, comprising M428L/N434S Fc mutations (EU numbering)) (FIG. 52A) and S309 N55Q LS GAALIE (also referred to herein as S309 N55Q MLNS GAALIE, comprising G236A, A330L, I332E, M428L, and N434S Fc mutations (EU numbering)) (FIG. 52B) to cell surface-expressed SARS-CoV-2 Spike protein, as measured by flow cytometry. See Example 29. Data are expressed as the percentage of cells identified as positive for antibody binding. Results shown are from one experiment and representative of three independent individual experiments performed.

FIG. 53 shows binding of antibodies S309 N55Q MLNS and S309 N55Q MLNS GAALIE to human FcγRIIa (both low affinity R131 and high affinity H131 alleles), FcγRIIIa (both low affinity F158 and high affinity V158 alleles), and FCyRIIb, using SPR. See Example 30. Biotinylated purified FcγRs were captured on the sensor chip surface prior to injection of the antibody. Association and dissociation profiles (separated by the vertical dotted line in each graph) were measured in real time as change in the SPR signal.

FIG. 54 shows binding of antibodies S309 (VH: SEQ ID NO.:105; VL: SEQ ID NO.:168) LS (also referred to herein as S309 MLNS, comprising M428L/N434S Fc mutations), S309 N55Q (VH: SEQ ID NO.:113; VL: SEQ ID NO.:168) LS (also referred to herein as S309 N55Q MLNS, comprising M428L/N434S Fc mutations (EU numbering)), and S309 N55Q LS GAALIE (also referred to herein as S309 N55Q MLNS GAALIE, comprising G236A, A330L, I332E, M428L, and N434S Fc mutations (EU numbering)) to complement component C1q, as measured by BLI on an Octet instrument. See Example 31. Association and dissociation profiles (separated by the vertical dotted line on the graph) were measured in real time as change in the interference pattern.

FIGS. 55A-55D show in vitro activation of human FcγRs by antibodies S309 (VH: SEQ ID NO.:105; VL: SEQ ID NO.:168) LS (also referred to herein as S309 MLNS, comprising M428L/N434S Fc mutations), S309 N55Q (VH: SEQ ID NO.:113; VL: SEQ ID NO.:168) LS (also referred to herein as S309 N55Q MLNS, comprising M428L/N434S Fc mutations) (EU numbering), and S309 N55Q LS GAALIE (also referred to herein as S309 N55Q MLNS GAALIE, comprising G236A, A330L, I332E, M428L, and N434S Fc mutations (EU numbering)), along with negative control antibody S309 GRLR. See Example 32. CHO cells stably transfected with the SARS-CoV-2 Spike protein served as antibody targets. Serial dilutions of antibody were incubated with target cells at room temperature for 15 minutes. Jurkat effector cells expressing the indicated FcγR and engineered with a NFAT-mediated luciferase reporter were resuspended in assay buffer and then added to assay plates. After incubation at 37° C. for 18 hours, Bio-Glo™ Luciferase Assay Reagent (Promega) was added and luminescence was quantified using a liminometer (Bio-Tek). Graphs show activation of human FcγRIIa (top left), FcγRIIb (top right), FcγRIIIa low affinity F158 allele (bottom left) and FCyRIIb high affinity V158 allele (bottom right). Data shown are means+/− standard deviation of duplicates.

FIGS. 56A and 56B show in vitro NK cell mediated killing (ADCC) of cells expressing SARS-CoV-2 Spike protein in the presence of antibodies S309 (VH: SEQ ID NO.:105; VL: SEQ ID NO.:168) LS (also referred to herein as S309 MLNS, comprising M428L/N434S Fc mutations), S309 N55Q (VH: SEQ ID NO.:105; VL: SEQ ID NO.:168) LS (also referred to herein as S309 N55Q MLNS, comprising M428L/N434S Fc mutations (EU numbering)), or S309 N55Q LS GAALIE (also referred to herein as S309 N55Q MLNS GAALIE, comprising G236A, A330L, I332E, M428L, and N434S Fc mutations (EU numbering)), or control antibody S309 GRLR. See Example 33. Serial dilutions of antibody (serially diluted 10-fold in AIM-V Medium from 40,000 ng/ml to 0.075 ng/ml) were incubated with CHO-CoV-2 Spike cells for 10 minutes before mixing with NK cells for 4 hours. NK cells were freshly isolated from two donors previously genotyped for homozygous expression of low-affinity (F/F158; FIG. 56A) or high-affinity (V/V158; FIG. 56B). ADCC was measured using LDH release assay. Data shown are means+/− standard deviation of quadruplicates.

FIG. 57 shows in vitro monocyte-mediated phagocytosis (ADCP) of cells expressing SARS-CoV-2 Spike protein in the presence of antibodies S309 (VH: SEQ ID NO.:105; VL: SEQ ID NO.:168) LS (also referred to herein as S309 MLNS, comprising M428L/N434S Fc mutations), S309 N55Q (VH: SEQ ID NO.:113; VL: SEQ ID NO.:168) LS (also referred to herein as S309 N55Q MLNS, comprising M428L and N434S Fc mutations (EU numbering)), or S309 N55Q LS GAALIE (also referred to herein as S309 N55Q MLNS GAALIE, comprising G236A, A330L, I332E, M428L, and N434S Fc mutations (EU numbering)), or control antibody S309 GRLR. See Example 33. Antibodies were incubated with PKH67-labeled CHO-CoV-2-Spike cells for 10 minutes before mixing with freshly isolated, cell trace violet labeled PBMCs. ADCP activity was measured after overnight incubation by flow cytometry as percentage of CD14+ monocytes that were double positive for PKH67 and cell trace violet. Data shown are means+/− standard deviation of duplicates.

FIGS. 58A and 58B show that antibody S309 (VH: SEQ ID NO.:105; VL: SEQ ID NO.:168) inhibits SARS-CoV-2 Spike protein-mediated cell-cell fusion. See Example 34. FIG. 58A shows micrographs of cells engineered to over-express SARS-CoV-2 Spike protein in the presence (bottom panel) or absence (upper panel) of S309. FIG. 58B shows quantified data from the fusion inhibition assay at various concentrations of antibody.

FIG. 59 provides data from a focus-forming units (FFU) assay showing that S309 N55Q variant antibodies do not cause antibody-mediated enhancement of SARS-CoV-2 replication in human donor-derived PBMCs or dendritic cells. See Example 35.

FIG. 60 shows expression (immunofluorescence) of DC-SIGN/L-SIGN, DC-SIGN, and ACE2 transgenes in HEK293T cells engineered to overexpress the indicated protein. See Example 37.

FIG. 61 shows VSV pseudovirus infection levels in wild-type HEK293T cells and in HEK293T cells engineered to overexpress DC-SIGN, L-SIGN, or ACE2. The pseudovirus expressed a recombinant SARS-CoV-2 spike protein with luciferase reporter. See Example 37.

FIG. 62 shows neutralization by monoclonal antibody S309 (VH of SEQ ID NO.:105, VL of SEQ ID NO.:168) of VSV pseudovirus infection in HEK293T cells engineered to overexpress DC-SIGN, L-SIGN, or ACE2. In this example, antibody S309 includes M428L and N434S Fc mutations (EU numbering). See Example 37.

FIG. 63 shows live SARS-CoV-2 infection levels in wild-type HEK293T cells and in HEK293T cells engineered to overexpress DC-SIGN, L-SIGN, or ACE2. Infection was determined using a recombinant S protein with luciferase reporter. See Example 37.

FIG. 64 shows neutralization by exemplary monoclonal antibody S309 (VH of SEQ ID NO.:105, VL of SEQ ID NO.:168) of live SARS-CoV-2 infection in HEK293T cells engineered to overexpress DC-SIGN, L-SIGN, or ACE2. In this example, antibody S309 includes M428L and N434S Fc mutations (EU numbering). See Example 37.

FIG. 65 shows expression (immunofluorescence) of L-SIGN, DC-SIGN, SIGLEC1, and ACE2 transgenes in HEK293T cells engineered to overexpress the indicated protein(s). See Example 37.

FIG. 66 shows live SARS-CoV-2 infection levels in wild-type HEK293T cells and in HEK293T cells engineered to overexpress DC-SIGN, L-SIGN, SIGLEC-1, or ACE2. Infection was determined using a recombinant S protein with luciferase reporter. See Example 37.

FIG. 67 shows neutralization by exemplary monoclonal antibody S309 (VH of SEQ ID NO.:105, VL of SEQ ID NO.:168) of live SARS-CoV-2 infection in HEK293T cells engineered to overexpress DC-SIGN, L-SIGN, SIGLEC-1, or ACE2. In this example, antibody S309 includes M428L and N434S Fc mutations (EU numbering). See Example 37.

FIGS. 68A and 68B show expression analysis of receptor proteins including CD209 (DC-SIGN) and SIGLEC proteins in several cell types. Size of dot correlates with the percentage of cells of the indicated type that express the protein, and intensity of dot shading correlates with the expression level of the protein. See Example 37.

FIG. 69 shows infection by live SARS-CoV-2 expressing N-luciferase in HEK293T cells (“parental”) or HEK293T cells stably expressing DC-SIGN, L-SIGN, SIGLEC-1, or ACE2. Data represent experiments testing SARS-CoV-2 at three multiplicities of infection (MOI). See Example 37.

FIG. 70 shows infection by SARS-CoV-2 pseudotyped VSV in HEK293T cells, HeLa cells, and MRCS cells transiently transduced with lentivirus to express DC-SIGN, L-SIGN, SIGLEC-1, or ACE2. Uninfected cells are shown as negative control. See Example 37.

FIGS. 71A and 71B show binding (as measured by biolayer interferometry) of S309, S309 N55Q MLNS, S309 N55Q MLNS GAALIE (FIG. 71A), and comparator antibodies REGN10933 and REGN10987 (FIG. 71B) to WT and mutated variants of RBD. See Example 39.

FIG. 72 shows neutralization of SARS-CoV-2 (“WT”=Wuhan-Hu-1; “UK”=SARS-CoV-2 variant B.1.1.7; and “SA”=variant B.1.351) MLV pseudovirus in Vero-E6 cells by S309 antibodies, as described in Example 39. Comparator antibodies REGN10987, REGN10933, and the combination of REGN10987+REGN10933 were also assessed.

FIGS. 73A-73D show that S309 (VH SEQ ID NO.:105; VL SEQ ID NO.:168) provides robust in vivo protection against SARS-CoV-2 challenge. Syrian hamsters were injected with the indicated amount of mAb 48 hours before intra-nasal challenge with SARS-CoV-2. (A) Quantification of viral RNA in the lungs 4 days post-infection. (B) Quantification of replicating virus in lung homogenates harvested 4 days post infection using a TCID50 assay. (C) Histological score of the lung tissue was assessed 4 days post infection. (D) The concentration of mAbs measured in the serum before infection (day 0) inversely correlates with the viral RNA load in the lung 4 days post infection. See Example 38.

DETAILED DESCRIPTION

Provided herein are antibodies and antigen-binding fragments that are capable binding to SARS-CoV-2 (e.g., a SARS-CoV-2 surface glycoprotein and/or RBD, as described herein, in a SARS-CoV-2 virion and/or expressed on the surface of a host cell, such as a cell infected by SARS-CoV-2). A host cell can be, for example, a lung cell, a CHO cell (such as, for example, an ExpiCHO cell transfected to express the surface glycoprotein), or the like. In certain embodiments, presently disclosed antibodies and antigen-binding fragments can neutralize a SARS-CoV-2 infection in an in vitro model of infection and/or in a human subject. Also provided are polynucleotides that encode the antibodies and antigen-binding fragments, vectors, host cells, and related compositions, as well as methods of using the antibodies, nucleic acids, vectors, host cells, and related compositions to treat (e.g., reduce, delay, eliminate, or prevent) a SARS-CoV-2 infection in a subject and/or in the manufacture of a medicament for treating a SARS-CoV-2 infection in a subject.

Prior to setting forth this disclosure in more detail, it may be helpful to an understanding thereof to provide definitions of certain terms to be used herein. Additional definitions are set forth throughout this disclosure.

As used herein, “SARS-CoV-2”, also referred to herein as “Wuhan coronavirus”, or “Wuhan seafood market pneumonia virus”, or “Wuhan CoV”, or “novel CoV”, or “nCoV”, or “2019 nCoV”, or “Wuhan nCoV” is a betacoronavirus believed to be of lineage B (sarbecovirus). SARS-CoV-2 was first identified in Wuhan, Hubei province, China, in late 2019 and spread within China and to other parts of the world by early 2020. Symptoms of SARS-CoV-2 include fever, dry cough, and dyspnea.

The genomic sequence of SARS-CoV-2 isolate Wuhan-Hu-1 is provided in SEQ ID NO.:163 (see also GenBank MN908947.3, Jan. 23, 2020), and the amino acid translation of the genome is provided in SEQ ID NO.:164 (see also GenBank QHD43416.1, Jan. 23, 2020). Like other coronaviruses (e.g., SARS CoV), SARS-CoV-2 comprises a “spike” or surface (“S”) type I transmembrane glycoprotein containing a receptor binding domain (RBD). RBD is believed to mediate entry of the lineage B SARS coronavirus to respiratory epithelial cells by binding to the cell surface receptor angiotensin-converting enzyme 2 (ACE2). In particular, a receptor binding motif (RBM) in the virus RBD is believed to interact with ACE2.

The amino acid sequence of the SARS-CoV-2 Wuhan-Hu-1 surface glycoprotein (S) is provided in SEQ ID NO.:165. Antibodies and antigen-binding fragments of the present disclosure are capable of binding to a SARS CoV-2 surface glycoprotein (S), such as that of Wuhan-Hu-1. For example, in certain embodiments, an antibody or antigen-binding fragment binds to an epitope in Wuhan-Hu-1 S protein RBD.

The amino acid sequence of SARS-CoV-2 Wuhan-Hu-1 RBD is provided in SEQ ID NO.:166. SARS-CoV-2 Wuhan-Hu-1 S protein has approximately 73% amino acid sequence identity with SARS-CoV S protein. The amino acid sequence of SARS-CoV-2 Wuhan-Hu-1 RBM is provided in SEQ ID NO.:167. SARS-CoV-2 RBD has approximately 75% to 77% amino acid sequence similarity to SARS coronavirus RBD, and SARS-CoV-2 Wuhan Hu-1RBM has approximately 50% amino acid sequence similarity to SARS coronavirus RBM.

Unless otherwise indicated herein, SARS-CoV-2 Wuhan Hu-1 refers to a virus comprising the amino acid sequence set forth in any one or more of SEQ ID NOs.:164, 165, and 166, optionally with the genomic sequence set forth in SEQ ID NO.:163.

There have been a number of emerging SARS-CoV-2 variants. Some SARS-CoV-2 variants contain an N439K mutation, which has enhanced binding affinity to the human ACE2 receptor (Thomson, E. C., et al., The circulating SARS-CoV-2 spike variant N439K maintains fitness while evading antibody-mediated immunity. bioRxiv, 2020). Some SARS-CoV-2 variants contain an N501Y mutation, which is associated with increased transmissibility, including the lineages B.1.1.7 (also known as 20I/501Y.Vi1 and VOC 202012/01; (de169-70, de1144, N501Y, A570D, D614G, P681H, T7161, S982A, and D1118H mutations)) and B.1.351 (also known as 20H/501Y.V2; L18F, D80A, D215G, R246I, K417N, E484K, N501Y, D614G, and A701V mutations), which were discovered in the United Kingdom and South Africa, respectively (Tegally, H., et al., Emergence and rapid spread of a new severe acute respiratory syndrome-related coronavirus 2 (SARS-CoV-2) lineage with multiple spike mutations in South Africa. medRxiv, 2020: p. 2020.12.21.20248640; Leung, K., et al., Early empirical assessment of the N501Y mutant strains of SARS-CoV-2 in the United Kingdom, October to November 2020. medRxiv, 2020: p. 2020.12.20.20248581). B.1.351 also include two other mutations in the RBD domain of SARS-CoV2 spike protein, K417N and E484K (Tegally, H., et al., Emergence and rapid spread of a new severe acute respiratory syndrome-related coronavirus 2 (SARS-CoV-2) lineage with multiple spike mutations in South Africa. medRxiv, 2020: p. 2020.12.21.20248640). Other SARS-CoV-2 variants include the Lineage B.1.1.28, which was first reported in Brazil; the Variant P.1, lineage B.1.1.28 (also known as 20J/501Y.V3), which was first reported in Japan; Variant L452R, which was first reported in California in the United States (Pan American Health Organization, Epidemiological update: Occurrence of variants of SARS-CoV-2 in the Americas, Jan. 20, 2021, available at reliefweb.int/sites/reliefweb.int/files/resources/2021-jan-20-phe-epi-update-SARS-CoV-2.pdf). Other SARS-CoV-2 variants include a SARS CoV-2 of clade 19A; SARS CoV-2 of clade 19B; a SARS CoV-2 of clade 20A; a SARS CoV-2 of clade 20B; a SARS CoV-2 of clade 20C; a SARS CoV-2 of clade 20D; a SARS CoV-2 of clade 20E (EU1); a SARS CoV-2 of clade 20F; a SARS CoV-2 of clade 20G; and SARS CoV-2 B1.1.207; and other SARS CoV-2 lineages described in Rambaut, A., et al., A dynamic nomenclature proposal for SARS-CoV-2 lineages to assist genomic epidemiology. Nat Microbiol 5, 1403-1407 (2020). The foregoing SARS-CoV-2 variants, and the amino acid and nucleotide sequences thereof, are incorporated herein by reference.

In the present description, any concentration range, percentage range, ratio range, or integer range is to be understood to include the value of any integer within the recited range and, when appropriate, fractions thereof (such as one tenth and one hundredth of an integer), unless otherwise indicated. Also, any number range recited herein relating to any physical feature, such as polymer subunits, size or thickness, are to be understood to include any integer within the recited range, unless otherwise indicated. As used herein, the term “about” means±20% of the indicated range, value, or structure, unless otherwise indicated. It should be understood that the terms “a” and “an” as used herein refer to “one or more” of the enumerated components. The use of the alternative (e.g., “or”) should be understood to mean either one, both, or any combination thereof of the alternatives. As used herein, the terms “include,” “have,” and “comprise” are used synonymously, which terms and variants thereof are intended to be construed as non-limiting.

“Optional” or “optionally” means that the subsequently described element, component, event, or circumstance may or may not occur, and that the description includes instances in which the element, component, event, or circumstance occurs and instances in which they do not.

In addition, it should be understood that the individual constructs, or groups of constructs, derived from the various combinations of the structures and subunits described herein, are disclosed by the present application to the same extent as if each construct or group of constructs was set forth individually. Thus, selection of particular structures or particular subunits is within the scope of the present disclosure.

The term “consisting essentially of” is not equivalent to “comprising” and refers to the specified materials or steps of a claim, or to those that do not materially affect the basic characteristics of a claimed subject matter. For example, a protein domain, region, or module (e.g., a binding domain) or a protein “consists essentially of” a particular amino acid sequence when the amino acid sequence of a domain, region, module, or protein includes extensions, deletions, mutations, or a combination thereof (e.g., amino acids at the amino- or carboxy-terminus or between domains) that, in combination, contribute to at most 20% (e.g., at most 15%, 10%, 8%, 6%, 5%, 4%, 3%, 2% or 1%) of the length of a domain, region, module, or protein and do not substantially affect (i.e., do not reduce the activity by more than 50%, such as no more than 40%, 30%, 25%, 20%, 15%, 10%, 5%, or 1%) the activity of the domain(s), region(s), module(s), or protein (e.g., the target binding affinity of a binding protein).

As used herein, “amino acid” refers to naturally occurring and synthetic amino acids, as well as amino acid analogs and amino acid mimetics that function in a manner similar to the naturally occurring amino acids. Naturally occurring amino acids are those encoded by the genetic code, as well as those amino acids that are later modified, e.g., hydroxyproline, γ-carboxyglutamate, and O-phosphoserine. Amino acid analogs refer to compounds that have the same basic chemical structure as a naturally occurring amino acid, i.e., an α-carbon that is bound to a hydrogen, a carboxyl group, an amino group, and an R group, e.g., homoserine, norleucine, methionine sulfoxide, methionine methyl sulfonium. Such analogs have modified R groups (e.g., norleucine) or modified peptide backbones, but retain the same basic chemical structure as a naturally occurring amino acid. Amino acid mimetics refer to chemical compounds that have a structure that is different from the general chemical structure of an amino acid, but that functions in a manner similar to a naturally occurring amino acid.

As used herein, “mutation” refers to a change in the sequence of a nucleic acid molecule or polypeptide molecule as compared to a reference or wild-type nucleic acid molecule or polypeptide molecule, respectively. A mutation can result in several different types of change in sequence, including substitution, insertion or deletion of nucleotide(s) or amino acid(s).

A “conservative substitution” refers to amino acid substitutions that do not significantly affect or alter binding characteristics of a particular protein. Generally, conservative substitutions are ones in which a substituted amino acid residue is replaced with an amino acid residue having a similar side chain. Conservative substitutions include a substitution found in one of the following groups: Group 1: Alanine (Ala or A), Glycine (Gly or G), Serine (Ser or S), Threonine (Thr or T); Group 2: Aspartic acid (Asp or D), Glutamic acid (Glu or Z); Group 3: Asparagine (Asn or N), Glutamine (Gln or Q); Group 4: Arginine (Arg or R), Lysine (Lys or K), Histidine (His or H); Group 5: Isoleucine (Ile or I), Leucine (Leu or L), Methionine (Met or M), Valine (Val or V); and Group 6: Phenylalanine (Phe or F), Tyrosine (Tyr or Y), Tryptophan (Trp or W). Additionally or alternatively, amino acids can be grouped into conservative substitution groups by similar function, chemical structure, or composition (e.g., acidic, basic, aliphatic, aromatic, or sulfur-containing). For example, an aliphatic grouping may include, for purposes of substitution, Gly, Ala, Val, Leu, and Ile. Other conservative substitutions groups include: sulfur-containing: Met and Cysteine (Cys or C); acidic: Asp, Glu, Asn, and Gln; small aliphatic, nonpolar or slightly polar residues: Ala, Ser, Thr, Pro, and Gly; polar, negatively charged residues and their amides: Asp, Asn, Glu, and Gln; polar, positively charged residues: His, Arg, and Lys; large aliphatic, nonpolar residues: Met, Leu, Ile, Val, and Cys; and large aromatic residues: Phe, Tyr, and Trp. Additional information can be found in Creighton (1984) Proteins, W.H. Freeman and Company.

As used herein, “protein” or “polypeptide” refers to a polymer of amino acid residues. Proteins apply to naturally occurring amino acid polymers, as well as to amino acid polymers in which one or more amino acid residue is an artificial chemical mimetic of a corresponding naturally occurring amino acid, and non-naturally occurring amino acid polymers. Variants of proteins, peptides, and polypeptides of this disclosure are also contemplated. In certain embodiments, variant proteins, peptides, and polypeptides comprise or consist of an amino acid sequence that is at least 70%, 75%, 80%, 85%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99%, or 99.9% identical to an amino acid sequence of a defined or reference amino acid sequence as described herein.

“Nucleic acid molecule” or “polynucleotide” or “polynucleic acid” refers to a polymeric compound including covalently linked nucleotides, which can be made up of natural subunits (e.g., purine or pyrimidine bases) or non-natural subunits (e.g., morpholine ring). Purine bases include adenine, guanine, hypoxanthine, and xanthine, and pyrimidine bases include uracil, thymine, and cytosine. Nucleic acid molecules include polyribonucleic acid (RNA), which includes mRNA, microRNA, siRNA, viral genomic RNA, and synthetic RNA, and polydeoxyribonucleic acid (DNA), which includes cDNA, genomic DNA, and synthetic DNA, either of which may be single or double stranded. If single-stranded, the nucleic acid molecule may be the coding strand or non-coding (anti-sense) strand. A nucleic acid molecule encoding an amino acid sequence includes all nucleotide sequences that encode the same amino acid sequence. Some versions of the nucleotide sequences may also include intron(s) to the extent that the intron(s) would be removed through co- or post-transcriptional mechanisms. In other words, different nucleotide sequences may encode the same amino acid sequence as the result of the redundancy or degeneracy of the genetic code, or by splicing.

Variants of nucleic acid molecules of this disclosure are also contemplated. Variant nucleic acid molecules are at least 70%, 75%, 80%, 85%, 90%, and are preferably 95%, 96%, 97%, 98%, 99%, or 99.9% identical a nucleic acid molecule of a defined or reference polynucleotide as described herein, or that hybridize to a polynucleotide under stringent hybridization conditions of 0.015M sodium chloride, 0.0015M sodium citrate at about 65-68° C. or 0.015M sodium chloride, 0.0015M sodium citrate, and 50% formamide at about 42° C. Nucleic acid molecule variants retain the capacity to encode a binding domain thereof having a functionality described herein, such as binding a target molecule.

“Percent sequence identity” refers to a relationship between two or more sequences, as determined by comparing the sequences. Preferred methods to determine sequence identity are designed to give the best match between the sequences being compared. For example, the sequences are aligned for optimal comparison purposes (e.g., gaps can be introduced in one or both of a first and a second amino acid or nucleic acid sequence for optimal alignment). Further, non-homologous sequences may be disregarded for comparison purposes. The percent sequence identity referenced herein is calculated over the length of the reference sequence, unless indicated otherwise. Methods to determine sequence identity and similarity can be found in publicly available computer programs. Sequence alignments and percent identity calculations may be performed using a BLAST program (e.g., BLAST 2.0, BLASTP, BLASTN, or BLASTX). The mathematical algorithm used in the BLAST programs can be found in Altschul et al., Nucleic Acids Res. 25:3389-3402, 1997. Within the context of this disclosure, it will be understood that where sequence analysis software is used for analysis, the results of the analysis are based on the “default values” of the program referenced. “Default values” mean any set of values or parameters which originally load with the software when first initialized.

The term “isolated” means that the material is removed from its original environment (e.g., the natural environment if it is naturally occurring). For example, a naturally occurring nucleic acid or polypeptide present in a living animal is not isolated, but the same nucleic acid or polypeptide, separated from some or all of the co-existing materials in the natural system, is isolated. Such nucleic acid could be part of a vector and/or such nucleic acid or polypeptide could be part of a composition (e.g., a cell lysate), and still be isolated in that such vector or composition is not part of the natural environment for the nucleic acid or polypeptide. “Isolated” can, in some embodiments, also describe an antibody, antigen-binding fragment, polynucleotide, vector, host cell, or composition that is outside of a human body.

The term “gene” means the segment of DNA or RNA involved in producing a polypeptide chain; in certain contexts, it includes regions preceding and following the coding region (e.g., 5′ untranslated region (UTR) and 3′ UTR) as well as intervening sequences (introns) between individual coding segments (exons).

A “functional variant” refers to a polypeptide or polynucleotide that is structurally similar or substantially structurally similar to a parent or reference compound of this disclosure, but differs slightly in composition (e.g., one base, atom or functional group is different, added, or removed), such that the polypeptide or encoded polypeptide is capable of performing at least one function of the parent polypeptide with at least 50% efficiency, preferably at least 55%, 60%, 70%, 75%, 80%, 85%, 90%, 95%, 96%, 97%, 98%, 99%, 99.9%, or 100% level of activity of the parent polypeptide. In other words, a functional variant of a polypeptide or encoded polypeptide of this disclosure has “similar binding,” “similar affinity” or “similar activity” when the functional variant displays no more than a 50% reduction in performance in a selected assay as compared to the parent or reference polypeptide, such as an assay for measuring binding affinity (e.g., Biacore® or tetramer staining measuring an association (Ka) or a dissociation (K_(D)) constant).

As used herein, a “functional portion” or “functional fragment” refers to a polypeptide or polynucleotide that comprises only a domain, portion or fragment of a parent or reference compound, and the polypeptide or encoded polypeptide retains at least 50% activity associated with the domain, portion or fragment of the parent or reference compound, preferably at least 55%, 60%, 70%, 75%, 80%, 85%, 90%, 95%, 96%, 97%, 98%, 99%, 99.9%, or 100% level of activity of the parent polypeptide, or provides a biological benefit (e.g., effector function). A “functional portion” or “functional fragment” of a polypeptide or encoded polypeptide of this disclosure has “similar binding” or “similar activity” when the functional portion or fragment displays no more than a 50% reduction in performance in a selected assay as compared to the parent or reference polypeptide (preferably no more than 20% or 10%, or no more than a log difference as compared to the parent or reference with regard to affinity).

As used herein, the term “engineered,” “recombinant,” or “non-natural” refers to an organism, microorganism, cell, nucleic acid molecule, or vector that includes at least one genetic alteration or has been modified by introduction of an exogenous or heterologous nucleic acid molecule, wherein such alterations or modifications are introduced by genetic engineering (i.e., human intervention). Genetic alterations include, for example, modifications introducing expressible nucleic acid molecules encoding functional RNA, proteins, fusion proteins or enzymes, or other nucleic acid molecule additions, deletions, substitutions, or other functional disruption of a cell's genetic material. Additional modifications include, for example, non-coding regulatory regions in which the modifications alter expression of a polynucleotide, gene, or operon.

As used herein, “heterologous” or “non-endogenous” or “exogenous” refers to any gene, protein, compound, nucleic acid molecule, or activity that is not native to a host cell or a subject, or any gene, protein, compound, nucleic acid molecule, or activity native to a host cell or a subject that has been altered. Heterologous, non-endogenous, or exogenous includes genes, proteins, compounds, or nucleic acid molecules that have been mutated or otherwise altered such that the structure, activity, or both is different as between the native and altered genes, proteins, compounds, or nucleic acid molecules. In certain embodiments, heterologous, non-endogenous, or exogenous genes, proteins, or nucleic acid molecules (e.g., receptors, ligands, etc.) may not be endogenous to a host cell or a subject, but instead nucleic acids encoding such genes, proteins, or nucleic acid molecules may have been added to a host cell by conjugation, transformation, transfection, electroporation, or the like, wherein the added nucleic acid molecule may integrate into a host cell genome or can exist as extra-chromosomal genetic material (e.g., as a plasmid or other self-replicating vector). The term “homologous” or “homolog” refers to a gene, protein, compound, nucleic acid molecule, or activity found in or derived from a host cell, species, or strain. For example, a heterologous or exogenous polynucleotide or gene encoding a polypeptide may be homologous to a native polynucleotide or gene and encode a homologous polypeptide or activity, but the polynucleotide or polypeptide may have an altered structure, sequence, expression level, or any combination thereof. A non-endogenous polynucleotide or gene, as well as the encoded polypeptide or activity, may be from the same species, a different species, or a combination thereof.

In certain embodiments, a nucleic acid molecule or portion thereof native to a host cell will be considered heterologous to the host cell if it has been altered or mutated, or a nucleic acid molecule native to a host cell may be considered heterologous if it has been altered with a heterologous expression control sequence or has been altered with an endogenous expression control sequence not normally associated with the nucleic acid molecule native to a host cell. In addition, the term “heterologous” can refer to a biological activity that is different, altered, or not endogenous to a host cell. As described herein, more than one heterologous nucleic acid molecule can be introduced into a host cell as separate nucleic acid molecules, as a plurality of individually controlled genes, as a polycistronic nucleic acid molecule, as a single nucleic acid molecule encoding an antibody or antigen-binding fragment (or other polypeptide), or any combination thereof.

As used herein, the term “endogenous” or “native” refers to a polynucleotide, gene, protein, compound, molecule, or activity that is normally present in a host cell or a subject.

The term “expression”, as used herein, refers to the process by which a polypeptide is produced based on the encoding sequence of a nucleic acid molecule, such as a gene. The process may include transcription, post-transcriptional control, post-transcriptional modification, translation, post-translational control, post-translational modification, or any combination thereof. An expressed nucleic acid molecule is typically operably linked to an expression control sequence (e.g., a promoter).

The term “operably linked” refers to the association of two or more nucleic acid molecules on a single nucleic acid fragment so that the function of one is affected by the other. For example, a promoter is operably linked with a coding sequence when it is capable of affecting the expression of that coding sequence (i.e., the coding sequence is under the transcriptional control of the promoter). “Unlinked” means that the associated genetic elements are not closely associated with one another and the function of one does not affect the other.

As described herein, more than one heterologous nucleic acid molecule can be introduced into a host cell as separate nucleic acid molecules, as a plurality of individually controlled genes, as a polycistronic nucleic acid molecule, as a single nucleic acid molecule encoding a protein (e.g., a heavy chain of an antibody), or any combination thereof. When two or more heterologous nucleic acid molecules are introduced into a host cell, it is understood that the two or more heterologous nucleic acid molecules can be introduced as a single nucleic acid molecule (e.g., on a single vector), on separate vectors, integrated into the host chromosome at a single site or multiple sites, or any combination thereof. The number of referenced heterologous nucleic acid molecules or protein activities refers to the number of encoding nucleic acid molecules or the number of protein activities, not the number of separate nucleic acid molecules introduced into a host cell.

The term “construct” refers to any polynucleotide that contains a recombinant nucleic acid molecule (or, when the context clearly indicates, a fusion protein of the present disclosure). A (polynucleotide) construct may be present in a vector (e.g., a bacterial vector, a viral vector) or may be integrated into a genome. A “vector” is a nucleic acid molecule that is capable of transporting another nucleic acid molecule. Vectors may be, for example, plasmids, cosmids, viruses, a RNA vector or a linear or circular DNA or RNA molecule that may include chromosomal, non-chromosomal, semi-synthetic or synthetic nucleic acid molecules. Vectors of the present disclosure also include transposon systems (e.g., Sleeping Beauty, see, e.g., Geurts et al., Mol. Ther. 8:108, 2003: Mát{tilde over (e)}s et al., Nat. Genet. 41:753, 2009). Exemplary vectors are those capable of autonomous replication (episomal vector), capable of delivering a polynucleotide to a cell genome (e.g., viral vector), or capable of expressing nucleic acid molecules to which they are linked (expression vectors).

As used herein, “expression vector” or “vector” refers to a DNA construct containing a nucleic acid molecule that is operably linked to a suitable control sequence capable of effecting the expression of the nucleic acid molecule in a suitable host. Such control sequences include a promoter to effect transcription, an optional operator sequence to control such transcription, a sequence encoding suitable mRNA ribosome binding sites, and sequences which control termination of transcription and translation. The vector may be a plasmid, a phage particle, a virus, or simply a potential genomic insert. Once transformed into a suitable host, the vector may replicate and function independently of the host genome, or may, in some instances, integrate into the genome itself or deliver the polynucleotide contained in the vector into the genome without the vector sequence. In the present specification, “plasmid,” “expression plasmid,” “virus,” and “vector” are often used interchangeably.

The term “introduced” in the context of inserting a nucleic acid molecule into a cell, means “transfection”, “transformation,” or “transduction” and includes reference to the incorporation of a nucleic acid molecule into a eukaryotic or prokaryotic cell wherein the nucleic acid molecule may be incorporated into the genome of a cell (e.g., chromosome, plasmid, plastid, or mitochondrial DNA), converted into an autonomous replicon, or transiently expressed (e.g., transfected mRNA).

In certain embodiments, polynucleotides of the present disclosure may be operatively linked to certain elements of a vector. For example, polynucleotide sequences that are needed to effect the expression and processing of coding sequences to which they are ligated may be operatively linked. Expression control sequences may include appropriate transcription initiation, termination, promoter, and enhancer sequences; efficient RNA processing signals such as splicing and polyadenylation signals; sequences that stabilize cytoplasmic mRNA; sequences that enhance translation efficiency (i.e., Kozak consensus sequences); sequences that enhance protein stability; and possibly sequences that enhance protein secretion. Expression control sequences may be operatively linked if they are contiguous with the gene of interest and expression control sequences that act in trans or at a distance to control the gene of interest.

In certain embodiments, the vector comprises a plasmid vector or a viral vector (e.g., a lentiviral vector or a γ-retroviral vector). Viral vectors include retrovirus, adenovirus, parvovirus (e.g., adeno-associated viruses), coronavirus, negative strand RNA viruses such as ortho-myxovirus (e.g., influenza virus), rhabdovirus (e.g., rabies and vesicular stomatitis virus), paramyxovirus (e.g., measles and Sendai), positive strand RNA viruses such as picornavirus and alphavirus, and double-stranded DNA viruses including adenovirus, herpesvirus (e.g., Herpes Simplex virus types 1 and 2, Epstein-Barr virus, cytomegalovirus), and poxvirus (e.g., vaccinia, fowlpox, and canarypox). Other viruses include, for example, Norwalk virus, togavirus, flavivirus, reoviruses, papovavirus, hepadnavirus, and hepatitis virus. Examples of retroviruses include avian leukosis-sarcoma, mammalian C-type, B-type viruses, D type viruses, HTLV-BLV group, lentivirus, spumavirus (Coffin, J. M., Retroviridae: The viruses and their replication, In Fundamental Virology, Third Edition, B. N. Fields et al., Eds., Lippincott-Raven Publishers, Philadelphia, 1996).

“Retroviruses” are viruses having an RNA genome, which is reverse-transcribed into DNA using a reverse transcriptase enzyme, the reverse-transcribed DNA is then incorporated into the host cell genome. “Gammaretrovirus” refers to a genus of the retroviridae family. Examples of gammaretroviruses include mouse stem cell virus, murine leukemia virus, feline leukemia virus, feline sarcoma virus, and avian reticuloendotheliosis viruses.

“Lentiviral vectors” include HIV-based lentiviral vectors for gene delivery, which can be integrative or non-integrative, have relatively large packaging capacity, and can transduce a range of different cell types. Lentiviral vectors are usually generated following transient transfection of three (packaging, envelope, and transfer) or more plasmids into producer cells. Like HIV, lentiviral vectors enter the target cell through the interaction of viral surface glycoproteins with receptors on the cell surface. On entry, the viral RNA undergoes reverse transcription, which is mediated by the viral reverse transcriptase complex. The product of reverse transcription is a double-stranded linear viral DNA, which is the substrate for viral integration into the DNA of infected cells.

In certain embodiments, the viral vector can be a gammaretrovirus, e.g., Moloney murine leukemia virus (MLV)-derived vectors. In other embodiments, the viral vector can be a more complex retrovirus-derived vector, e.g., a lentivirus-derived vector. HIV-1-derived vectors belong to this category. Other examples include lentivirus vectors derived from HIV-2, FIV, equine infectious anemia virus, SIV, and Maedi-Visna virus (ovine lentivirus). Methods of using retroviral and lentiviral viral vectors and packaging cells for transducing mammalian host cells with viral particles containing transgenes are known in the art and have been previous described, for example, in: U.S. Pat. No. 8,119,772; Walchli et al., PLoS One 6:327930, 2011; Zhao et al., J. Immunol. 174:4415, 2005; Engels et al., Hum. Gene Ther. 14:1155, 2003; Frecha et al., Mol. Ther. 18:1748, 2010; and Verhoeyen et al., Methods Mol. Biol. 506:97, 2009. Retroviral and lentiviral vector constructs and expression systems are also commercially available. Other viral vectors also can be used for polynucleotide delivery including DNA viral vectors, including, for example adenovirus-based vectors and adeno-associated virus (AAV)-based vectors; vectors derived from herpes simplex viruses (HSVs), including amplicon vectors, replication-defective HSV and attenuated HSV (Krisky et al., Gene Ther. 5:1517, 1998).

Other vectors that can be used with the compositions and methods of this disclosure include those derived from baculoviruses and α-viruses. (Jolly, D J. 1999. Emerging Viral Vectors. pp 209-40 in Friedmann T. ed. The Development of Human Gene Therapy. New York: Cold Spring Harbor Lab), or plasmid vectors (such as sleeping beauty or other transposon vectors).

When a viral vector genome comprises a plurality of polynucleotides to be expressed in a host cell as separate transcripts, the viral vector may also comprise additional sequences between the two (or more) transcripts allowing for bicistronic or multicistronic expression. Examples of such sequences used in viral vectors include internal ribosome entry sites (IRES), furin cleavage sites, viral 2A peptide, or any combination thereof.

Plasmid vectors, including DNA-based antibody or antigen-binding fragment-encoding plasmid vectors for direct administration to a subject, are described further herein.

As used herein, the term “host” refers to a cell or microorganism targeted for genetic modification with a heterologous nucleic acid molecule to produce a polypeptide of interest (e.g., an antibody of the present disclosure).

A host cell may include any individual cell or cell culture which may receive a vector or the incorporation of nucleic acids or express proteins. The term also encompasses progeny of the host cell, whether genetically or phenotypically the same or different. Suitable host cells may depend on the vector and may include mammalian cells, animal cells, human cells, simian cells, insect cells, yeast cells, and bacterial cells. These cells may be induced to incorporate the vector or other material by use of a viral vector, transformation via calcium phosphate precipitation, DEAE-dextran, electroporation, microinjection, or other methods. See, for example, Sambrook et al., Molecular Cloning: A Laboratory Manual 2d ed. (Cold Spring Harbor Laboratory, 1989).

In the context of a SARS-CoV-2 infection, a “host” refers to a cell or a subject (e.g., a human) infected with SARS-CoV-2.

“Antigen” or “Ag”, as used herein, refers to an immunogenic molecule that provokes an immune response. This immune response may involve antibody production, activation of specific immunologically-competent cells, activation of complement, antibody dependent cytotoxicicity, or any combination thereof. An antigen (immunogenic molecule) may be, for example, a peptide, glycopeptide, polypeptide, glycopolypeptide, polynucleotide, polysaccharide, lipid, or the like. It is readily apparent that an antigen can be synthesized, produced recombinantly, or derived from a biological sample. Exemplary biological samples that can contain one or more antigens include tissue samples, stool samples, cells, biological fluids, or combinations thereof. Antigens can be produced by cells that have been modified or genetically engineered to express an antigen. Antigens can also be present in a SARS-CoV-2 (e.g., a surface glycoprotein or portion thereof), such as present in a virion, or expressed or presented on the surface of a cell infected by SARS-CoV-2.

The term “epitope” or “antigenic epitope” includes any molecule, structure, amino acid sequence, or protein determinant that is recognized and specifically bound by a cognate binding molecule, such as an immunoglobulin, or other binding molecule, domain, or protein. Epitopic determinants generally contain chemically active surface groupings of molecules, such as amino acids or sugar side chains, and can have specific three-dimensional structural characteristics, as well as specific charge characteristics. Where an antigen is or comprises a peptide or protein, the epitope can be comprised of consecutive amino acids (e.g., a linear epitope), or can be comprised of amino acids from different parts or regions of the protein that are brought into proximity by protein folding (e.g., a discontinuous or conformational epitope), or non-contiguous amino acids that are in close proximity irrespective of protein folding.

Antibodies and Antigen-Binding Fragments

In one aspect, the present disclosure provides an isolated antibody, or an antigen-binding fragment thereof, that comprises a heavy chain variable domain (VH) comprising a CDRH1, a CDRH2, and a CDRH3, and a light chain variable domain (VL) comprising a CDRL1, a CDRL2, and a CDRL3, and is capable of binding to a surface glycoprotein (S) of SARS-CoV-2. In certain embodiments, the antibody or antigen-binding fragment is capable of binding to a SARS-CoV-2 surface glycoprotein (S) expressed on a cell surface of a host cell and/or on a SARS-CoV-2 virion.

In certain embodiments, an antibody or antigen-binding fragment of the present disclosure associates with or unites with a SARS-CoV-2 surface glycoprotein epitope or antigen comprising the epitope, while not significantly associating or uniting with any other molecules or components in a sample.

In certain embodiments, an antibody or antigen-binding fragment of the present disclosure associates with or unites (e.g., binds) to a SARS-CoV-2 surface glycoprotein epitope, and can also associate with or unite with an epitope from another coronavirus (e.g., SARS CoV) present in the sample, but not significantly associating or uniting with any other molecules or components in the sample. In other words, in certain embodiments, an antibody or antigen binding fragment of the present disclosure is cross-reactive for SARS-CoV-2 and one or more additional coronavirus.

In certain embodiments, an antibody or antigen-binding fragment of the present disclosure specifically binds to a SARS-CoV-2 surface glycoprotein. As used herein, “specifically binds” refers to an association or union of an antibody or antigen-binding fragment to an antigen with an affinity or K_(a) (i.e., an equilibrium association constant of a particular binding interaction with units of 1/M) equal to or greater than 10⁵ M⁻¹ (which equals the ratio of the on-rate [K_(on)] to the off rate [K_(off)] for this association reaction), while not significantly associating or uniting with any other molecules or components in a sample. Alternatively, affinity may be defined as an equilibrium dissociation constant (K_(d)) of a particular binding interaction with units of M (e.g., 10⁻⁵ M to 10⁻¹³ M). Antibodies may be classified as “high-affinity” antibodies or as “low-affinity” antibodies. “High-affinity” antibodies refer to those antibodies having a K_(a) of at least 10⁷M⁻¹, at least 10⁸ M⁻¹, at least 10⁹ M⁻¹, at least 10¹⁰ M⁻¹, at least 10¹¹ M⁻¹, at least 10¹²M⁻¹, or at least 10¹³ M⁻¹. “Low-affinity” antibodies refer to those antibodies having a K_(a) of up to 10⁷M⁻¹, up to 10⁶ M⁻¹, up to 10⁵ M⁻¹. Alternatively, affinity may be defined as an equilibrium dissociation constant (K_(a)) of a particular binding interaction with units of M (e.g., 10⁻⁵ M to 10⁻¹³ M).

In some contexts, antibody and antigen-binding fragments may be described with reference to affinity and/or to avidity for antigen. Unless otherwise indicated, avidity refers to the total binding strength of an antibody or antigen-binding fragment thereof to antigen, and reflects binding affinity, valency of the antibody or antigen-binding fragment (e.g., whether the antibody or antigen-binding fragment comprises one, two, three, four, five, six, seven, eight, nine, ten, or more binding sites), and, for example, whether another agent is present that can affect the binding (e.g., a non-competitive inhibitor of the antibody or antigen-binding fragment).

A variety of assays are known for identifying antibodies of the present disclosure that bind a particular target, as well as determining binding domain or binding protein affinities, such as Western blot, ELISA (e.g., direct, indirect, or sandwich), analytical ultracentrifugation, spectroscopy, and surface plasmon resonance (Biacore®) analysis (see, e.g., Scatchard et al., Ann. N.Y. Acad. Sci. 51:660, 1949; Wilson, Science 295:2103, 2002; Wolff et al., Cancer Res. 53:2560, 1993; and U.S. Pat. Nos. 5,283,173, 5,468,614, or the equivalent). Assays for assessing affinity or apparent affinity or relative affinity are also known.

In certain examples, binding can be determined by recombinantly expressing a SARS-CoV-2 antigen in a host cell (e.g., by transfection) and immunostaining the (e.g., fixed, or fixed and permeabilized) host cell with antibody and analyzing binding by flow cytometery (e.g., using a ZE5 Cell Analyzer (BioRad®) and FlowJo software (TreeStar). In some embodiments, positive binding can be defined by differential staining by antibody of SARS-CoV-2-expressing cells versus control (e.g., mock) cells.

In some embodiments an antibody or antigen-binding fragment of the present disclosure binds to SARS-CoV-2 S protein, as measured using biolayer interferometry. In certain embodiments, an antibody or antigen-binding fragment of the present disclosure binds to SARS-CoV-2 S protein with a K_(D) of less than about 4.5×10⁻⁹M, less than about 5×10⁻⁹M, less than about 1×10⁻¹⁰ M, less than about 5×10⁻¹⁰ M, less than about 1×10⁻¹¹ M, less than about 5×10⁻¹¹ M, less than about 1×10⁻¹² M, or less than about 5×10⁻¹² M. In some embodiments, an antibody or antigen-binding fragment of the present disclosure binds to SARS-CoV-2 S protein RBD with a K_(D) of less than about 4.5×10⁻⁹M, less than about 5×10⁻⁹M, less than about 1×10⁻¹⁰ M, less than about 5×10⁻¹⁰ M, less than about 1×10⁻¹¹ M, less than about 5×10⁻¹¹ M, less than about 1×10¹² M, or less than about 5×10⁻¹² M. In certain embodiments, an antibody or antigen-binding fragment of the present disclosure binds to SARS-CoV-2 S protein (e.g., a glycosylated or a deglycosylated S protein RBD) with a K_(D), a k_(a), and/or a k_(d) as shown in Table 8, Table 9, or Table 10 herein.

In particular embodiments, an antibody or antigen-binding fragment is capable of binding to a glycosylated S protein RBD with a K_(D) of about 0.35 nM, about 0.36 nM, about 0.37 nM, about 0.38 nM, about 0.39 nM, about 0.40 nM, about 0.41 nM, about 0.42 nM, about 0.43 nM, about 0.44 nM, about 0.45 nM, about 0.46 nM, about 0.47 nM, about 0.48 nM, about 0.49 nM, about 0.50 nM, about 0.51 nM, or about 1.7 nM, optionally as measured by surface plasmon resonance, and/or with a k_(a) of about 8.5e4 1/Ms, about 8.6e4 1/Ms, about 8.7e4 1/Ms, about 8.8e4 1/Ms, about 8.9e4 1/Ms, about 9.0e4 1/Ms, about 9.1e4 1/Ms, about 9.2e4 1/Ms, about 9.3e4 1/Ms, about 9.4e4 1/Ms, about 9.5e4 1/Ms, about 9.6e4 1/Ms, about 9.7e4 1/Ms, about 9.8e4 1/Ms, about 9.9e4 1/Ms, or about 1.0e5 1/Ms, optionally as measured by surface plasmon resonance, and/or with a k_(d) of about 1.6e-4 1/S, about 3.3e-5 1/S, about 3.4e-5 1/S, about 3.5e-5 1/S, about 3.6e-5 1/S, about 3.7e-5 1/S, about 3.8e-5 1/S, about 3.9e-5 1/S, about 4.0e-5 1/S, about 4.1e-5 1/S, about 4.2e-5 1/S, about 4.3e-5 1/S, about 4.4e-5 1/S, about 4.5e-5 1/S, about 4.6e-5 1/S, about 4.7e-5 1/S, about 4.8e-5 1/S, about 4.9e-5 1/S, about 5.0e-5 1/S, about 5.1e-5 1/S, about 5.2e-5 1/S, about 5.3e-5 1/S, about 5.4e-5 1/S, about 5.5e-5 1/S, about 5.6e-5 1/S, about 5.7e-5 1/S, about 5.8e-5 1/S, about 5.9e-5 1/S, about 6.0e-5 1/S, about 6.1e-5 1/S, about 6.2e-5 1/S, about 6.3e-5 1/S, about 6.4e-5 1/S, or about 6.5e-5 1/S, optionally as measured by surface plasmon resonance.

In certain embodiments, an antibody or antigen-binding fragment is capable of binding to a deglycosylated S protein RBD with a K_(D) of about 0.95, about 0.96 nM, about 0.97 nM, about 0.98 nM, about 0.99 nM, about 1.0 nM, about 1.1 nM, about 1.2 nM, about 1.3 nM, about 1.4 nM, about 1.5 nM, or about 1.6 nM, optionally as measured by surface plasmon resonance, and/or with a k_(a) of about (1/S) about 2.5e5, about 2.6e5, about 2.7e5, about 2.8e5, about 2.9e5, about 3.0e5, about 3.1e5, optionally as measured by surface plasmon resonance, and/or with a k_(d) of (1/S) about 2.8e-4, about 2.9e-4, about 3.0e-4, about 3.1e-4, about 3.2e-4, about 3.3e-4, about 3.4e-4, about 3.5e-4, about 3.6e-4, about 3.7e-4, about 3.8e-4, about 3.9e-4, about 4.0e-4, about 4.1e-4, about 4.2e-4, about 4.3e-4, about 4.4e-4, about 4.5e-4, about 4.6e-4, about 4.7e-4, about 4.8e-4, about 4.9e-4, or about 5.0e-4, optionally as measured by surface plasmon resonance.

In some embodiments for determining binding to RBD, surface plasmon resonance comprises using conducted using a sensor chip with anti-human Fc covalently immobilized (e.g., from GE). Buffer can be 10 mM HEPES pH 7.4, 150 mM NaCl, 3 mM EDTA, and 0.05% P20 detergent. SPR can be conducted at 25° C. Antibodies can be diluted from supernatant to approximately 2 μg/ml. RBD concentrations can be 0.8 nM, 3.1 nM, 12.5 nM, 50 nM, and/or 200 nM.

In some embodiments, an antibody or antigen-binding fragment is capable of binding to a Receptor Binding Domain (RBD) of the SARS-CoV-2 surface glycoprotein when the RBD is glycosylated and/or when the RBD is deglycosylated, wherein the binding is determined using surface plasmon resonance (SPR), wherein, optionally: (1) the SPR is performed using a Biacore T200 instrument using a single-cycle kinetics approach, further optionally with a 3 minute injection period and a 20 minute dissociation period; (2) the antibody or antigen-binding fragment is captured on a surface; (3) the RBD is present at a concentration of 0.8 nM, 3.1 nM, 12.5 nM, 50 nM, or 200 nM; (4) the antibody or antigen-binding fragment binds to the glycosylated RBD with a KD of about 2.0 nM, about 1.9 nM, about 1.8 nM, about 1.7 nM, about 1.6 nM, about 1.5 nM, about 1.4 nM, about 1.3 nM, about 1.2 nM, about 1.1 nM, about 1.0 nM, about 0.9 nM, about 0.8 nM, about 0.7 nM, about 0.6 nM, about 0.5 nM, or about 0.4 nM, or with a KD of 0.4 nM±0.05 nM, or with a KD of 0.45 nM±0.05 nM, or with a KD of 0.5 nM±0.05 nM, or with a KD of 0.6 nM±0.05 nM, or with a KD of 0.7 nM±0.05 nM, or with a KD of 1.7 nM±0.05 nM; and/or (5) the antibody or antigen-binding fragment binds to the deglycosylated RBD with a KD of about 37.0 nM, about 8.0 nM, about 2.0 nM, about 1.9 nM, about 1.8 nM, about 1.7 nM, about 1.6 nM, about 1.5 nM, about 1.4 nM, about 1.3 nM, about 1.2 nM, about 1.1 nM, about 1.0 nM, or about 0.9 nM, or with a KD of 37.0 nM±0.05 nM, or with a KD of 8.0 nM 0.05 nM, or with a KD of 1.0 nM±0.05 nM, or with a KD of 0.9 nM±0.05 nM, or with a KD of 1.3 nM±0.05 nM, or with a KD of 1.8 nM±0.05 nM, or with a KD of 1.7 nM±0.05 nM.

In certain embodiments, an antibody of the present disclosure is capable of neutralizing infection by SARS-CoV-2. As used herein, a “neutralizing antibody” is one that can neutralize, i.e., prevent, inhibit, reduce, impede, or interfere with, the ability of a pathogen to initiate and/or perpetuate an infection in a host. Neutralization may be quantified by, for example, assessing SARS-CoV-2 RNA levels in a (n e.g. lung) sample, assessing SARS-CoV-2 viral load in a (n e.g. lung) sample, assessing histopathology of a (n e.g. lung) sample, or the like. The terms “neutralizing antibody” and “an antibody that neutralizes” or “antibodies that neutralize” are used interchangeably herein. In any of the presently disclosed embodiments, the antibody or antigen-binding fragment is capable of preventing and/or neutralizing a SARS-CoV-2 infection in an in vitro model of infection and/or in an in vivo animal model of infection (e.g., using a Syrian hamster model with intranasal delivery of SARS-CoV-2) and/or in a human. In some embodiments, an antibody or antigen-binding fragment of the present disclosure is capable of neutralizing a SARS-CoV-2 infection with an IC90 of about 9 μg/ml. In some embodiments, an antibody or antigen-binding fragment of the present disclosure is capable of neutralizing a SARS-CoV-2 infection with an IC50 of about 16 to about 20 μg/ml. In some embodiments, an antibody or antigen-binding fragment is capable of neutralizing a SARS-CoV-2 infection, or a virus pseudotyped with SARS-CoV-2, with an IC50 of about 0.3 to about 0.4 μg/ml. In some embodiments, an antibody or antigen-binding fragment, or a composition comprising two or more antibodies or antigen-binding fragments, of the present disclosure is capable of neutralizing a SARS-CoV-2 infection, or a virus pseudotyped with SARS-CoV-2, with an IC50 of about 0.07 to about 0.08 μg/ml.

In certain embodiments, the antibody or antigen-binding fragment (i) recognizes an epitope in the ACE2 receptor binding motif (RBM, SEQ ID NO.:167) of SARS-CoV-2; (ii) is capable of blocking an interaction between SARS-CoV-2 and ACE2; (ii) is capable of binding to SARS-CoV-2 S protein with greater avidity than to SARS coronavirus S protein; (iv) is capable of staining about 30%, about 35%, about 40%, about 50%, about 55%, about 56%, about 57%, about 58%, about 59%, about 60%, or more of target cells expressing SARS-CoV-2 surface glycoprotein in a sample comprising about 50,000 of the target cells (e.g., ExpiCHO cells) in approximately 1004, when the antibody or antigen-binding fragment is present at 10 μg/ml (e.g., staining as determined by a flow cytometry ELISA); (v) recognizes an epitope that is conserved in the ACE2 RBM of SARS-CoV-2 and in an ACE2 RBM of SARS coronavirus; (vi) is cross-reactive against SARS-CoV-2 and SARS coronavirus; (vii) recognizes an epitope in the SARS-CoV-2 surface glycoprotein that is not in the ACE2 RBM; or (viii) any combination of (i)-(vii).

In some embodiments, an antibody or antigen-binding fragment thereof is capable of capable of inhibiting an interaction between: (i) SARS-CoV-2 and a human DC-SIGN; (ii) SARS-CoV-2 and a human L-SIGN; (iii) SARS-CoV-2 and a human SIGLEC-1; or (iv) any combination of (i)-(iii). As disclosed herein, DC-SIGN, L-SIGN, and SIGLEC-1 can be involved in a SARS-CoV-2 infection, in roles comprising those of attachment receptors. Inhibiting an interaction between SARS-CoV-2 and DC-SIGN, L-SIGN, and/or SIGLEC-1 can, in some contexts, neutralize infection by the SARS-CoV-2.

In some embodiments, an antibody or antigen-binding fragment thereof is capable of binding to a surface glycoprotein of: (i) a SARS-CoV-2 Wuhan-Hu-1 (SEQ ID NO.:165); (ii) a SARS-CoV-2 B.1.1.7; (iii) a SARS-CoV-2 B.1.351; (iv) a SARS-CoV-2 comprising any one or more of the following substitution mutations relative to SEQ ID NO.:165: N501Y; S477N; N439K; L452R; E484K; Y453F; A520S; K417N; K417V; S494P; N501T; 5477R; V367F; P384L; A522S; A522V; V382L; P330S; T478I; S477I; P479S; or (v) any combination of (i)-(iv).

Terms understood by those in the art of antibody technology are each given the meaning acquired in the art, unless expressly defined differently herein. For example, the term “antibody” refers to an intact antibody comprising at least two heavy (H) chains and two light (L) chains inter-connected by disulfide bonds, as well as any antigen-binding portion or fragment of an intact antibody that has or retains the ability to bind to the antigen target molecule recognized by the intact antibody, such as an scFv, Fab, or Fab′2 fragment. Thus, the term “antibody” herein is used in the broadest sense and includes polyclonal and monoclonal antibodies, including intact antibodies and functional (antigen-binding) antibody fragments thereof, including fragment antigen binding (Fab) fragments, F(ab′)2 fragments, Fab′ fragments, Fv fragments, recombinant IgG (rIgG) fragments, single chain antibody fragments, including single chain variable fragments (scFv), and single domain antibodies (e.g., sdAb, sdFv, nanobody) fragments. The term encompasses genetically engineered and/or otherwise modified forms of immunoglobulins, such as intrabodies, peptibodies, chimeric antibodies, fully human antibodies, humanized antibodies, and heteroconjugate antibodies, multispecific, e.g., bispecific antibodies, diabodies, triabodies, tetrabodies, tandem di-scFv, and tandem tri-scFv. Unless otherwise stated, the term “antibody” should be understood to encompass functional antibody fragments thereof. The term also encompasses intact or full-length antibodies, including antibodies of any class or sub-class, including IgG and sub-classes thereof (IgG1, IgG2, IgG3, IgG4), IgM, IgE, IgA, and IgD.

The terms “VL” or “VL” and “VH” or “VH” refer to the variable binding region from an antibody light chain and an antibody heavy chain, respectively. In certain embodiments, a VL is a kappa (κ) class (also “VK” herein). In certain embodiments, a VL is a lambda (λ) class. The variable binding regions comprise discrete, well-defined sub-regions known as “complementarity determining regions” (CDRs) and “framework regions” (FRs). The terms “complementarity determining region,” and “CDR,” are synonymous with “hypervariable region” or “HVR,” and refer to sequences of amino acids within antibody variable regions, which, in general, together confer the antigen specificity and/or binding affinity of the antibody, wherein consecutive CDRs (i.e., CDR1 and CDR2, CDR2 and CDR3) are separated from one another in primary structure by a framework region. There are three CDRs in each variable region (HCDR1, HCDR2, HCDR3; LCDR1, LCDR2, LCDR3; also referred to as CDRHs and CDRLs, respectively). In certain embodiments, an antibody VH comprises four FRs and three CDRs as follows: FR1-HCDR1-FR2-HCDR2-FR3-HCDR3-FR4; and an antibody VL comprises four FRs and three CDRs as follows: FR1-LCDR1-FR2-LCDR2-FR3-LCDR3-FR4. In general, the VH and the VL together form the antigen-binding site through their respective CDRs.

As used herein, a “variant” of a CDR refers to a functional variant of a CDR sequence having up to 1-3 amino acid substitutions (e.g., conservative or non-conservative substitutions), deletions, or combinations thereof.

Numbering of CDR and framework regions may be according to any known method or scheme, such as the Kabat, Chothia, EU, IMGT, and AHo numbering schemes (see, e.g., Kabat et al., “Sequences of Proteins of Immunological Interest, US Dept. Health and Human Services, Public Health Service National Institutes of Health, 1991, 5^(th) ed.; Chothia and Lesk, J. Mol. Biol. 196:901-917 (1987)); Lefranc et al., Dev. Comp. Immunol. 27:55, 2003; Honegger and Pluckthun, J. Mol. Bio. 309:657-670 (2001)). Equivalent residue positions can be annotated and for different molecules to be compared using Antigen receptor Numbering And Receptor Classification (ANARCI) software tool (2016, Bioinformatics 15:298-300). Accordingly, identification of CDRs of an exemplary variable domain (VH or VL) sequence as provided herein according to one numbering scheme is not exclusive of an antibody comprising CDRs of the same variable domain as determined using a different numbering scheme. In certain embodiments, an antibody or antigen-binding fragment is provided that comprises CDRs from a VH sequence according to any one of SEQ ID NOs.:113, 1, 9-15, 23, 24, 27, 28-46, 55, 63, 79, 87, 95, 103, 105, 114-120, 129-146, 155, 172, 176-178, 194, 196, 198, 200, 202, 239, and 267, and from a VL sequence according to any one of SEQ ID NOs.:168, 5, 47-50, 59, 67, 71-72, 75, 76, 83, 91, 99, 109, 147-150, 159, 182, 190, 234, and 243, as determined using any known CDR numbering method, including the Kabat, Chothia, EU, IMGT, Martin (Enhanced Chothia), Contact, and AHo numbering methods. In certain embodiments, CDRs are according to the IMGT numbering method. In certain embodiments, CDRs are according to the antibody numbering method developed by the Chemical Computing Group (CCG); e.g., using Molecular Operating Environment (MOE) software (www.chemcomp.com).

In certain embodiments, an antibody or an antigen-binding fragment is provided that comprises a heavy chain variable domain (VH) comprising a CDRH1, a CDRH2, and a CDRH3, and a light chain variable domain (VL) comprising a CDRL1, a CDRL2, and a CDRL3, wherein: (i) the CDRH1 comprises or consists of the amino acid sequence according to any one of SEQ ID NOs.:106, 2, 56, 64, 80, 88, 96, 156, 179, 195, or 240, or a sequence variant thereof comprising one, two, or three acid substitutions, one or more of which substitutions is optionally a conservative substitution and/or is a substitution to a germline-encoded amino acid; (ii) the CDRH2 comprises or consists of the amino acid sequence according to any one of SEQ ID NOs.:121, 3, 16-22, 57, 65, 81, 89, 97, 107, 122-126, 157, 180, 197, 199, or 241, or a sequence variant thereof comprising one, two, or three amino acid substitutions, one or more of which substitutions is optionally a conservative substitution and/or is a substitution to a germline-encoded amino acid; (iii) the CDRH3 comprises or consists of the amino acid sequence according to any one of SEQ ID NOs.:108, 4, 25, 26, 58, 66, 82, 90, 98, 104, 127, 128, 158, 181, 201, 203, or 242, or a sequence variant thereof comprising one, two, or three amino acid substitutions, one or more of which substitutions is optionally a conservative substitution and/or is a substitution to a germline-encoded amino acid; (iv) the CDRL1 comprises or consists of the amino acid sequence according to any one of SEQ ID NOs.:169, 6, 51-54, 60, 68, 73, 74, 84, 92, 100, 110, 160, 183, 235, or 244, or a sequence variant thereof comprising one, two, or three amino acid substitutions, one or more of which substitutions is optionally a conservative substitution and/or is a substitution to a germline-encoded amino acid; (v) the CDRL2 comprises or consists of the amino acid sequence according to any one of SEQ ID NOs.:170, 7, 61, 69, 85, 93, 101, 111, 161, 184, 236, or 245, or a sequence variant thereof comprising one, two, or three amino acid substitutions, one or more of which substitutions is optionally a conservative substitution and/or is a substitution to a germline-encoded amino acid; and/or (vi) the CDRL3 comprises or consists of the amino acid sequence according to any one of SEQ ID NOs.:171, 8, 62, 70, 77, 78, 86, 94, 102, 112, 151, 152, 153, 154, 162, 185, 237, or 246, or a sequence variant thereof comprising having one, two, or three amino acid substitutions, one or more of which substitutions is optionally a conservative substitution and/or is a substitution to a germline-encoded amino acid, wherein the antibody or antigen binding fragment is capable of binding to a SARS-CoV-2 surface glycoprotein expressed on a cell surface of a host cell, on a virion, or both

In some embodiments, an antibody or antigen-binding fragment comprises VH and VL amino acid sequences that are encoded by:

(i) a VH1-18 gene and a VK3-20 gene, respectively, or that are encoded by a polynucleotide having at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, or at least 99% identity to VH1-18 and VK3-20, respectively;

(ii) a VH3-7 allele and a VL3-25 allele, respectively, or that are encoded by a polynucleotide having at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, or at least 99% identity to VH3-7 and VL3-25, respectively;

(iii) a VH3-23 allele and a VK1-5 allele, respectively, or that are encoded by a polynucleotide having at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, or at least 99% identity to VH3-23 and VK1-5, respectively;

(iv) a VH3-13 allele and a VK1-39 allele respectively, or that are encoded by a polynucleotide having at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, or at least 99% identity to VH3-13 and VK1-39, respectively;

(v) a VH1-18 allele and a VK3-11 allele, respectively, or that are encoded by a polynucleotide having at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, or at least 99% identity to VH1-18 and VK3-11, respectively; or

(vi) a VH1-69 allele and a VL2-23 allele, respectively, or that are encoded by a polynucleotide having at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, or at least 99% identity to VH1-69 and VL2-23, respectively.

In any of the presently disclosed embodiments, the antibody or antigen-binding fragment is capable of preventing and/or neutralizing a SARS-CoV-2 infection in an in vitro model of infection and/or in an in vivo animal model of infection and/or in a human.

In any of the presently disclosed embodiments, the antibody or antigen-binding fragment comprises CDRH1, CDRH2, CDRH3, CDRL1, CDRL2, and CDRL3 amino acid sequences according to SEQ ID NOs.: (i) 2-4 and 6-8 or 235-237, respectively; (ii) 2, any one of 16-22, 4, and 6-8 or 235-237, respectively; (iii) 2, 3, any one of 25-26, and 6-8 or 235-237, respectively; (iv) 2-4, 51, 7, and 8, respectively; (v) 2-4, 52, 7 or 236, and 8 or 237, respectively; (vi) 2-4, 53, 7 or 236, and 8 or 237, respectively; (vii) 2-5, 54, 7 or 236, and 8 or 237, respectively; (viii) 56-58 and 60-62, respectively; (ix) 64-66 and 68-70, respectively; (x) 64-66, 73 or 74, 69, and 70, respectively; (xi) 64-66, 68-69, and 77 or 78, respectively; (xii) 80-82 and 84-86, respectively; (xiii) 88-90 and 92-94, respectively; (xiv) 96-98 and 101-102, respectively; (xv) 96, 97, 104, and 100-102, respectively; (xvi) 106-108 and 110-112 or 169-171, respectively; (xvii) 106, any one of 121-126, 108, and 110-112, respectively; (xviii) 106, 107, 127 or 128, and 110-112, respectively; (xix) 106-108, 110, 111, and 151, respectively; (xx) 106-108, 110, 111, and 152, respectively; (xxi) 106-108, 110, 111, and 153, respectively; (xxii) 106-108, 110, 111, and 154, respectively; (xxiii) 106, 107 or any one of 121-126, 108 or 127 or 128, and 169-171, respectively; (xxiv) 156-158 and 160-162, respectively; (xxv) 106, 123, 127, and 169-171, respectively; (xxvi) 2, 17, 25, 6 or 235 or any one of 51-54, 7 or 236, and 8 or 237, respectively; (xxvii) 2, 20, 25, 6 or 235 or any one of 51-54, 7 or 236, and 8 or 237 respectively; (xxviii) 179-181 and 183-185, respectively, (xxix) 195, 180, 181 and 183-185, respectively; (xxx) 195, 197, 181 and 183-185, respectively; (xxxi) 195, 199, 181 and 183-185, respectively; (xxxii) 195, 197, 201 and 183-185, respectively; (xxxiii) 195, 197, 203 and 183-185, respectively; (xxxiv) 195, 199, 201 and 183-185, respectively; (xxxv) 195, 199, 203 and 183-185, respectively; (xxxvi) 179, 180, 181 and 183-185, respectively; (xxxvii) 179, 197, 181 and 183-185, respectively; (xxxviii) 179, 199, 181 and 183-185, respectively; (xxxix) 179, 197, 201 and 183-185, respectively; (xxxx) 179, 197, 203 and 183-185, respectively; (xxxxi) 179, 199, 201 and 183-185, respectively; (xxxxii) 179, 199, 203 and 183-185, respectively; (xxxxiii) 179, 180, 201 and 183-185, respectively; (xxxxiv) 179, 180, 203 and 183-185, respectively; and (xxxxv) 240-242 and 244-246, respectively.

In certain embodiments, an antibody or an antigen-binding fragment of the present disclosure comprises CDRH1, CDRH2, CDRH3, CDRL1, CDRL2, and CDRL3 amino acid sequences as set forth in SEQ ID NOs: 80-82 and 84-86, respectively. In further embodiments, an antibody or antigen-binding fragment of the present disclosure binds to SARS-CoV-2 S protein with a K_(D) of less than about 4.5×10⁻⁹M, less than about 5×10⁻⁹M, less than about 1×10⁻¹⁰ M, less than about 5×10⁻¹⁰ M, less than about 1×10⁻¹¹M, less than about 5×10⁻¹¹M, less than about 1×10¹² M, or less than about 5×10¹² M. In still further embodiments, an antibody or antigen-binding fragment of the present disclosure is capable of neutralizing a SARS-CoV-2 infection, and/or of neutralizing infection of a target cell by a virus pseudotyped with SARS-CoV-2, with an IC50 of about 16 to about 20 μg/ml.

In certain embodiments, an antibody or an antigen-binding fragment of the present disclosure comprises CDRH1, CDRH2, CDRH3, CDRL1, CDRL2, and CDRL3 amino acid sequences as set forth in SEQ ID NOs: 106-108 and 169-171 or 106, 121, 108, and 169-171, respectively. In further embodiments, an antibody or antigen-binding fragment of the present disclosure binds to SARS-CoV-2 S protein with a K_(D) of less than about 4.5×10⁻⁹M, less than about 5×10⁻⁹M, less than about 1×10¹⁰ M, less than about 5×10⁻¹⁰ M, less than about 1×10⁻¹¹M, less than about 5×10⁻¹¹M, less than about 1×10¹² M, or less than about 5×10¹² M. In still further embodiments, an antibody or antigen-binding fragment of the present disclosure is capable of neutralizing a SARS-CoV-2 infection, and/or of neutralizing infection of a target cell by a virus pseudotyped with SARS-CoV-2, with an IC50 of about 0.3 to about 0.4 μg/ml.

In certain embodiments, an antibody or an antigen-binding fragment of the present disclosure comprises a CDRH1, a CDRH2, a CDRH3, a CDRL1, a CDRL2, and a CDRL3, wherein each CDR is independently selected from a corresponding CDR of SARS-CoV-2 S300 mAb, SARS-CoV-2 S300-v1 mAb, SARS-CoV-2 S300-v1.1 mAb, SARS-CoV-2 S300-v1.2 mAb, SARS-CoV-2 S300-v1.3 mAb, SARS-CoV-2 S300-v1.4 mAb, SARS-CoV-2 S300-v1.5 mAb, SARS-CoV-2 S300-v1.6 mAb, SARS-CoV-2 S300-v1.7 mAb, or SARS-CoV-2 S300-v1.8 mAb SARS-CoV-2 S300-v1.9 mAb, SARS-CoV-2 S300-v2 mAb, SARS-CoV-2 S300-v2.1 mAb, SARS-CoV-2 S300-v2.2 mAb, SARS-CoV-2 S300-v2.3 mAb, SARS-CoV-2 S300-v2.4 mAb, SARS-CoV-2 S300-v2.5 mAb, SARS-CoV-2 S300-v2.6 mAb, SARS-CoV-2 S300-v2.7 mAb, SARS-CoV-2 S300-v2.8 mAb, SARS-CoV-2 S300-v2.9 mAb, SARS-CoV-2 S300-v2.10, SARS-CoV-2 S300-v2.11, SARS-CoV-2 S300-v3 mAb, SARS-CoV-2 S300-v3.1 mAb, SARS-CoV-2 S300-v3.2 mAb, SARS-CoV-2 S300-v3.3 mAb, SARS-CoV-2 S300-v3.4 mAb, SARS-CoV-2 S300-v3.5 mAb, SARS-CoV-2 S300-v3.6 mAb, SARS-CoV-2 S300-v3.7 mAb, SARS-CoV-2 S300-v3.8 mAb, SARS-CoV-2 S300-v3.9 mAb, SARS-CoV-2 S300-v10 mAb, SARS-CoV-2 S300-v11 mAb, SARS-CoV-2 S300-v12 mAb, SARS-CoV-2 S300-v13 mAb, SARS-S300-v14 mAb, SARS-CoV-2 S302 mAb, SARS-CoV-2 S303 mAb, SARS-CoV-2 S303-v1 mAb, SARS-CoV-2 S303-v2 mAb, SARS-CoV-2 S303-v3 mAb, SARS-CoV-2 S303-v4 mAb, SARS-CoV-2 S303-v5 mAb, SARS-CoV-2 S304 mAb, SARS-CoV-2 S306 mAb, SARS-CoV-2 S307 mAb, SARS-CoV-2 S308 mAb, SARS-CoV-2 S308-v1 mAb, SARS-CoV-2 S308-v2 mAb, SARS-CoV-2 S309 mAb, SARS-CoV-2 S309-v1 mAb, SARS-CoV-2 S309-v1.1 mAb, SARS-CoV-2 S309-v1.2 mAb, SARS-CoV-2 S309-v1.3 mAb, SARS-CoV-2 S309-v1.4 mAb, SARS-CoV-2 S309-v1.5 mAb, SARS-CoV-2 S309-v1.6 mAb, SARS-CoV-2 S309-v1.7 mAb, SARS-CoV-2 S309-v1.8 mAb, SARS-CoV-2 S309-v2 mAb, SARS-CoV-2 S309-v2.1 mAb, SARS-CoV-2 S309-v2.2 mAb, SARS-CoV-2 S309-v2.3 mAb, SARS-CoV-2 S309-v2.4 mAb, SARS-CoV-2 S309-v2.5 mAb, SARS-CoV-2 S309-v2.6 mAb, SARS-CoV-2 S309-v2.7 mAb, SARS-CoV-2 S309-v2.8 mAb, SARS-CoV-2 S309-v2.9 mAb, SARS-CoV-2 S309-v3 mAb, SARS-CoV-2 S309-v3.1 mAb, SARS-CoV-2 S309-v3.2 mAb, SARS-CoV-2 S309-v3.3 mAb, SARS-CoV-2 S309-v3.4 mAb, SARS-CoV-2 S309-v3.5 mAb, SARS-CoV-2 S309-v3.6 mAb, SARS-CoV-2 S309-v3.7 mAb, SARS-CoV-2 S309-v3.8 mAb, SARS-CoV-2 S309-v9 mAb, SARS-CoV-2 S309-v10 mAb, SARS-CoV-2 S309-v11 mAb, SARS-CoV-2 S309-v12 mAb, SARS-CoV-2 S309-v13 mAb, SARS-CoV-2 S310 mAb, SARS-CoV-2 S311 mAb, SARS-CoV-2 S312 mAb, SARS-CoV-2 S315-v1 mAb, SARS-CoV-2 S315-v2 mAb, SARS-CoV-2 S315-v3 mAb, SARS-CoV-2 S315-v4 mAb, SARS-CoV-2 S315-v5 mAb, SARS-CoV-2 S315-v6 mAb, or SARS-CoV-2 S315-v7 mAb, as provided in Table 2. That is, all combinations of CDRs from SARS-CoV-2 mAbs and the variant sequences thereof provided in Table 2 are contemplated.

Exemplary antibodies of the present disclosure include antibody S309 and engineered variants thereof. In particular embodiments, an antibody or antigen-binding fragment comprises a CDRH1, a CDRH2, a CDRH3, a CDRL1, a CDRL2, and a CDRL3 selected from any of the CDRH1, CDRH2, CDRH3, CDRL1, CDRL2, and CDRL3 amino acid sequences (respectively) provided in Table 1.

In some embodiments, an antibody or antigen-binding fragment comprises: a CDRH1, a CDRH2, and a CDRH3 of the VH amino acid sequence set forth in any one of SEQ ID NOs.:105, 113, 114, 115, 116, 117, 118, 119, 120, 129, 130, 131, 132, 133, 134, 135, 136, 137, 138, 139, 140, 141, 142, 143, 144, 145, 146, 172, and 267; and a CDRL1, a CDRL2, and a CDRL3 as set forth in SEQ ID NO.:168 (i.e., according to any CDR numbering or determination method known in the art, such as IMGT, Kabat, Chothia, AHo, North, Contact, CCG, EU, or Martin (Enhanced Chothia)).

In further embodiments, the antibody or antigen-binding fragment comprises a VH having at least 85% identity (i.e., 85%, 86, 87, 88, 89, 90, 91, 92, 93, 94, 95, 96, 97, 98, 99, or 100%) identity to a VH amino acid sequence provided in Table 1 and/or a VL having at least 85% identity (i.e., 85%, 86, 87, 88, 89, 90, 91, 92, 93, 94, 95, 96, 97, 98, 99, or 100%) identity to a VL amino acid sequence provided in Table 1. In still further embodiments, the antibody or antigen-binding fragment comprises a VH having at least 90% identity identity to a VH amino acid sequence provided in Table 1 and/or a VL having at least 90% identity to a VL amino acid sequence provided in Table 1. In still further embodiments, the antibody or antigen-binding fragment comprises a VH having at least 95% identity identity to a VH amino acid sequence provided in Table 1 and/or a VL having at least 95% identity to a VL amino acid sequence provided in Table 1. In still further embodiments, the antibody or antigen-binding fragment comprises a VH having at least 99% identity identity to a VH amino acid sequence provided in Table 1 and/or a VL having at least 99% identity to a VL amino acid sequence provided in Table 1. In some embodiments, the antibody or antigen-binding fragment comprises a VH amino acid sequence selected from the VH amino acid sequences provided in Table 1 and a VL amino acid sequence selected from the VL amino acid sequence provided in Table 1.

TABLE 1 CDR (IMGT) and Variable Region Amino Acid  Sequences of Certain S309 Antibodies CDRH1 GYPFTSYG (SEQ ID NO.: 106) CDRH2 ISTYNGNT (SEQ ID NO.: 107); ISTYQGNT (SEQ ID  NO.: 121); ISTYNSNT (SEQ ID NO.: 122); ISTYNANT (SEQ ID  NO.: 123); ISTYNQNT (SEQ ID NO.: 124); ISTYLGNT (SEQ ID  NO.: 125); ISTYTGNT (SEQ ID NO.: 126) CDRH3 ARDYTRGAWFGESLIGGFDN (SEQ ID NO.: 108); ARDYTRGAFFGESLIGGFDN (SEQ ID NO.: 127); ARDYTRGAYFGESLIGGFDN (SEQ ID NO.: 128) VH QVQLVQSGAEVKKPGASVKVSCKASGYPFTSYGISWVRQAPGQGL EWMGWISTYNGNTNYAQKFQGRVTMTTDTSTTTGYMELRRLRSD DTAVYYCARDYTRGAWFGESLIGGFDNWGQGTLVTVSS (SEQ  ID NO.: 105) QVQLVQSGAEVKKPGASVKVSCKASGYPFTSYGISWVRQAPGQGL EWMGWISTYQGNTNYAQKFQGRVTMTTDTSTTTGYMELRRLRSD DTAVYYCARDYTRGAWFGESLIGGFDNWGQGTLVTVSS (SEQ  ID NO: 113) QVQLVQSGAEVKKPGASVKVSCKASGYPFTSYGISWVRQAPGQGL EWMGWISTYNSNTNYAQKFQGRVTMTTDTSTTTGYMELRRLRSDD TAVYYCARDYTRGAWFGESLIGGFDNWGQGTLVTVSS (SEQ ID NO.: 114) QVQLVQSGAEVKKPGASVKVSCKASGYPFTSYGISWVRQAPGQGL EWMGWISTYNANTNYAQKFQGRVTMTTDTSTTTGYMELRRLRSD DTAVYYCARDYTRGAWFGESLIGGFDNWGQGTLVTVSS (SEQ  ID NO: 115) QVQLVQSGAEVKKPGASVKVSCKASGYPFTSYGISWVRQAPGQGL EWMGWISTYNQNTNYAQKFQGRVTMTTDTSTTTGYMELRRLRSD DTAVYYCARDYTRGAWFGESLIGGFDNWGQGTLVTVSS (SEQ  ID NO.: 116) QVQLVQSGAEVKKPGASVKVSCKASGYPFTSYGISWVRQAPGQGL EWMGWISTYLGNTNYAQKFQGRVTMTTDTSTTTGYMELRRLRSD DTAVYYCARDYTRGAWFGESLIGGFDNWGQGTLVTVSS (SEQ  ID NO.: 117) QVQLVQSGAEVKKPGASVKVSCKASGYPFTSYGISWVRQAPGQGL EWMGWISTYTGNTNYAQKFQGRVTMTTDTSTTTGYMELRRLRSD DTAVYYCARDYTRGAWFGESLIGGFDNWGQGTLVTVSS (SEQ  ID NO.: 118) QVQLVQSGAEVKKPGASVKVSCKASGYPFTSYGISWVRQAPGQGL EWMGWISTYNGNTNYAQKFQGRVTMTTDTSTTTGYMELRRLRSD DTAVYYCARDYTRGAFFGESLIGGFDNWGQGTLVTVSS (SEQ  ID NO.: 119) QVQLVQSGAEVKKPGASVKVSCKASGYPFTSYGISWVRQAPGQGL EWMGWISTYNGNTNYAQKFQGRVTMTTDTSTTTGYMELRRLRSD DTAVYYCARDYTRGAYFGESLIGGFDNWGQGTLVTVSS (SEQ  ID NO.: 120) QVQLVQSGAEVKKPGASVKVSCKASGYPFTSYGISWVRQAPGQGL EWMGFISTYNGNTNYAQKFQGRVTMTTDTSTTTGYMELRRLRSDD TAVYYCARDYTRGAWFGESLIGGFDNWGQGTLVTVSS (SEQ ID NO.: 129) QVQLVQSGAEVKKPGASVKVSCKASGYPFTSYGISWVRQAPGQGL EWMGFISTYQGNTNYAQKFQGRVTMTTDTSTTTGYMELRRLRSDD TAVYYCARDYTRGAWFGESLIGGFDNWGQGTLVTVSS (SEQ ID NO.: 130) QVQLVQSGAEVKKPGASVKVSCKASGYPFTSYGISWVRQAPGQGL EWMGFISTYNSNTNYAQKFQGRVTMTTDTSTTTGYMELRRLRSDD TAVYYCARDYTRGAWFGESLIGGFDNWGQGTLVTVSS (SEQ ID NO.: 131) QVQLVQSGAEVKKPGASVKVSCKASGYPFTSYGISWVRQAPGQGL EWMGFISTYNANTNYAQKFQGRVTMTTDTSTTTGYMELRRLRSDD TAVYYCARDYTRGAWFGESLIGGFDNWGQGTLVTVSS (SEQ ID NO.: 132) QVQLVQSGAEVKKPGASVKVSCKASGYPFTSYGISWVRQAPGQGL EWMGFISTYNQNTNYAQKFQGRVTMTTDTSTTTGYMELRRLRSDD TAVYYCARDYTRGAWFGESLIGGFDNWGQGTLVTVSS (SEQ ID NO.: 133) QVQLVQSGAEVKKPGASVKVSCKASGYPFTSYGISWVRQAPGQGL EWMGFISTYLGNTNYAQKFQGRVTMTTDTSTTTGYMELRRLRSDD TAVYYCARDYTRGAWFGESLIGGFDNWGQGTLVTVSS (SEQ ID NO.: 134) QVQLVQSGAEVKKPGASVKVSCKASGYPFTSYGISWVRQAPGQGL EWMGFISTYTGNTNYAQKFQGRVTMTTDTSTTTGYMELRRLRSDD TAVYYCARDYTRGAWFGESLIGGFDNWGQGTLVTVSS (SEQ ID NO.: 135) QVQLVQSGAEVKKPGASVKVSCKASGYPFTSYGISWVRQAPGQGL EWMGFISTYNGNTNYAQKFQGRVTMTTDTSTTTGYMELRRLRSDD TAVYYCARDYTRGAFFGESLIGGFDNWGQGTLVTVSS (SEQ ID NO.: 136) QVQLVQSGAEVKKPGASVKVSCKASGYPFTSYGISWVRQAPGQGL EWMGFISTYNGNTNYAQKFQGRVTMTTDTSTTTGYMELRRLRSDD TAVYYCARDYTRGAYFGESLIGGFDNWGQGTLVTVSS (SEQ ID NO.: 137) QVQLVQSGAEVKKPGASVKVSCKASGYPFTSYGISWVRQAPGQGL EWMGYISTYNGNTNYAQKFQGRVTMTTDTSTTTGYMELRRLRSDD TAVYYCARDYTRGAWFGESLIGGFDNWGQGTLVTVSS (SEQ ID NO.: 138) QVQLVQSGAEVKKPGASVKVSCKASGYPFTSYGISWVRQAPGQGL EWMGYISTYQGNTNYAQKFQGRVTMTTDTSTTTGYMELRRLRSDD TAVYYCARDYTRGAWFGESLIGGFDNWGQGTLVTVSS (SEQ ID NO.: 139) QVQLVQSGAEVKKPGASVKVSCKASGYPFTSYGISWVRQAPGQGL EWMGYISTYNSNTNYAQKFQGRVTMTTDTSTTTGYMELRRLRSDD TAVYYCARDYTRGAWFGESLIGGFDNWGQGTLVTVSS (SEQ ID NO.: 140) QVQLVQSGAEVKKPGASVKVSCKASGYPFTSYGISWVRQAPGQGL EWMGYISTYNANTNYAQKFQGRVTMTTDTSTTTGYMELRRLRSDD TAVYYCARDYTRGAWFGESLIGGFDNWGQGTLVTVSS (SEQ ID NO.: 141) QVQLVQSGAEVKKPGASVKVSCKASGYPFTSYGISWVRQAPGQGL EWMGYISTYNQNTNYAQKFQGRVTMTTDTSTTTGYMELRRLRSDD TAVYYCARDYTRGAWFGESLIGGFDNWGQGTLVTVSS (SEQ ID NO.: 142) QVQLVQSGAEVKKPGASVKVSCKASGYPFTSYGISWVRQAPGQGL EWMGYISTYLGNTNYAQKFQGRVTMTTDTSTTTGYMELRRLRSDD TAVYYCARDYTRGAWFGESLIGGFDNWGQGTLVTVSS (SEQ ID NO.: 143) QVQLVQSGAEVKKPGASVKVSCKASGYPFTSYGISWVRQAPGQGL EWMGYISTYTGNTNYAQKFQGRVTMTTDTSTTTGYMELRRLRSDD TAVYYCARDYTRGAWFGESLIGGFDNWGQGTLVTVSS (SEQ ID NO.: 144) QVQLVQSGAEVKKPGASVKVSCKASGYPFTSYGISWVRQAPGQGL EWMGYISTYNGNTNYAQKFQGRVTMTTDTSTTTGYMELRRLRSDD TAVYYCARDYTRGAFFGESLIGGFDNWGQGTLVTVSS (SEQ ID NO.: 145) QVQLVQSGAEVKKPGASVKVSCKASGYPFTSYGISWVRQAPGQGL EWMGYISTYNGNTNYAQKFQGRVTMTTDTSTTTGYMELRRLRSDD TAVYYCARDYTRGAYFGESLIGGFDNWGQGTLVTVSS (SEQ ID NO.: 146) QVQLVQSGAEVKKPGASVKVSCKASGYPFTSYGISWVRQAPGQGL EWMGFISTYNANTNYAQKFQGRVTMTTDTSTTTGYMELRRLRSDD TAVYYCARDYTRGAFFGESLIGGFDNWGQGTLVTVSS (SEQ ID NO.: 172) QVQLVQSGAEVKKPGASVKVSCKASGYPFTSYGISWVRQAPGQGL EWMGX₁ ISTYX 2 X 3 NTNYAQKFQGRVTMTTDTSTTTGYMELRRLR SDDTAVYYCARDYTRGAX 4 FGESLIGGFDNWGQGTLVTVSS wherein X₁ = W, F, or Y; X₂ = N, Q, L, or T;  X₃ = G, S, A, or Q; X₄ = W, F, or Y (SEQ ID  NO.: 267) CDRL1 QTVSSTS (SEQ ID NO.: 169) CDRL2 GAS (SEQ ID NO.: 170) CDRL3 QQHDTSLT (SEQ ID NO.: 171) VL EIVLTQSPGTLSLSPGERATLSCRASQTVSSTSLAWYQQKPGQA PRLLIYGASSRATGIPDRFSGSGSGTDFTLTISRLEPEDFAVYY CQQHDTSLTFGGGTKVEIK (SEQ ID NO.: 168)

In particular embodiments, the antibody or antigen-binding fragment comprises CDRH1, CDRH2, and CDRH3 according to SEQ ID NOs.:106, 107 or 121 or 122 or 123 or 124 or 125 or 126, and 108 or 127 or 128, respectively, and CDRL1, CDRL2, and CDRL3 according to SEQ ID NOs.:169-171, respectively. In some embodiments, the antibody or antigen-binding fragment comprises the CDRH1, CDRH2, CDRH3, CDRL1, CDRL2, and CDRL3 amino acid sequences set forth in: (a) SEQ ID NOs.:106, 121, 108, 169, 170, and 171, respectively; (b) SEQ ID NOs.: 106, 121, 127, 169, 170, and 171, respectively; (c) SEQ ID NOs.: 106, 121, 128, 169, 170, and 171, respectively; (d) SEQ ID NOs.: 106, 107, 108, 169, 170, and 171, respectively; (e) SEQ ID NOs.: 106, 107, 127, 169, 170, and 171, respectively; (f) SEQ ID NOs.: 106, 107, 128, 169, 170, and 171, respectively; (g) SEQ ID NOs.: 106, 122, 108, 169, 170, and 171, respectively; (h) SEQ ID NOs.: 106, 122, 127, 169, 170, and 171, respectively; (i) SEQ ID NOs.: 106, 122, 128, 169, 170, and 171, respectively; (j) SEQ ID NOs.: 106, 123, 108, 169, 170, and 171, respectively; (k) SEQ ID NOs.: 106, 123, 127, 169, 170, and 171, respectively; (l) SEQ ID NOs.: 106, 123, 128, 169, 170, and 171, respectively; (m) SEQ ID NOs.: 106, 124, 108, 169, 170, and 171, respectively; (n) SEQ ID NOs.: 106, 124, 127, 169, 170, and 171, respectively; (o) SEQ ID NOs.: 106, 124, 128, 169, 170, and 171, respectively; (p) SEQ ID NOs.: 106, 125, 108, 169, 170, and 171, respectively; (q) SEQ ID NOs.: 106, 125, 127, 169, 170, and 171, respectively; (r) SEQ ID NOs.: 106, 125, 128, 169, 170, and 171, respectively; (s) SEQ ID NOs.: 106, 126, 108, 169, 170, and 171, respectively; (t) SEQ ID NOs.: 106, 126, 127, 169, 170, and 171, respectively; or (u) SEQ ID NOs.: 106, 126, 128, 169, 170, and 171, respectively.

In further embodiments, the VH comprises or consists of the amino acid sequence set forth in any one of SEQ ID NOs.:105, 113, 114, 115, 116, 117, 118, 119, 120, 129, 130, 131, 132, 133, 134, 135, 136, 137, 138, 139, 140, 141, 142, 143, 144, 145, 146, 172, and 267, and the VL comprises or consists of the amino acid sequence set forth in SEQ ID NO.:168.

The term “CL” refers to an “immunoglobulin light chain constant region” or a “light chain constant region,” i.e., a constant region from an antibody light chain. The term “CH” refers to an “immunoglobulin heavy chain constant region” or a “heavy chain constant region,” which is further divisible, depending on the antibody isotype into CH1, CH2, and CH3 (IgA, IgD, IgG), or CH1, CH2, CH3, and CH4 domains (IgE, IgM). The Fc region of an antibody heavy chain is described further herein. In any of the presently disclosed embodiments, an antibody or antigen-binding fragment of the present disclosure comprises any one or more of CL, a CH1, a CH2, and a CH3. In certain embodiments, a CL comprises an amino acid sequence having 90%, 91%, 92%, 93%, 94%, 95%, 96%, 975, 98%, 99%, or 100% identity to the amino acid sequence of SEQ ID NO.:174 or SEQ ID NO.:193. In certain embodiments, a CH1-CH2-CH3 comprises an amino acid sequence having 90%, 91%, 92%, 93%, 94%, 95%, 96%, 975, 98%, 99%, or 100% identity to the amino acid sequence of SEQ ID NO.:173 or SEQ ID NO.:175 or SEQ ID NO.:265 or SEQ ID NO.:266. It will be understood that, for example, production in a mammalian cell line can remove one or more C-terminal lysine of an antibody heavy chain (see, e.g., Liu et al. mAbs 6(5):1145-1154 (2014)). Accordingly, an antibody or antigen-binding fragment of the present disclosure can comprise a heavy chain, a CH1-CH3, a CH3, or an Fc polypeptide wherein a C-terminal lysine residue is present or is absent; in other words, encompassed are embodiments where the C-terminal residue of a heavy chain, a CH1-CH3, or an Fc polypeptide is not a lysine, and embodiments where a lysine is the C-terminal residue. In certain embodiments, a composition comprises a plurality of an antibody and/or an antigen-binding fragment of the present disclosure, wherein one or more antibody or antigen-binding fragment does not comprise a lysine residue at the C-terminal end of the heavy chain, CH1-CH3, or Fc polypeptide, and wherein one or more antibody or antigen-binding fragment comprises a lysine residue at the C-terminal end of the heavy chain, CH1-CH3, or Fc polypeptide.

A “Fab” (fragment antigen binding) is the part of an antibody that binds to antigens and includes the variable region and CH1 of the heavy chain linked to the light chain via an inter-chain disulfide bond. Each Fab fragment is monovalent with respect to antigen binding, i.e., it has a single antigen-binding site. Pepsin treatment of an antibody yields a single large F(ab′)2 fragment that roughly corresponds to two disulfide linked Fab fragments having divalent antigen-binding activity and is still capable of cross-linking antigen. Both the Fab and F(ab′)2 are examples of “antigen-binding fragments.” Fab′ fragments differ from Fab fragments by having additional few residues at the carboxy terminus of the CH1 domain including one or more cysteines from the antibody hinge region. Fab′-SH is the designation herein for Fab′ in which the cysteine residue(s) of the constant domains bear a free thiol group. F(ab′)2 antibody fragments originally were produced as pairs of Fab′ fragments that have hinge cysteines between them. Other chemical couplings of antibody fragments are also known.

Fab fragments may be joined, e.g., by a peptide linker, to form a single chain Fab, also referred to herein as “scFab.” In these embodiments, an inter-chain disulfide bond that is present in a native Fab may not be present, and the linker serves in full or in part to link or connect the Fab fragments in a single polypeptide chain. A heavy chain-derived Fab fragment (e.g., comprising, consisting of, or consisting essentially of VH+CH1, or “Fd”) and a light chain-derived Fab fragment (e.g., comprising, consisting of, or consisting essentially of VL+CL) may be linked in any arrangement to form a scFab. For example, a scFab may be arranged, in N-terminal to C-terminal direction, according to (heavy chain Fab fragment-linker-light chain Fab fragment) or (light chain Fab fragment-linker-heavy chain Fab fragment). Peptide linkers and exemplary linker sequences for use in scFabs are discussed in further detail herein.

A scFab can be comprise any combination of VH and VL sequences or any combination of the CDRH1, CDRH2, CDRH3, CDRL1, CDRL2, and CDRL3 sequences disclosed herein. In certain embodiments, a scFab comprises the VH sequence as provided in SEQ ID NO: 105 or SEQ ID NO: 113 and the VL sequence as provided in SEQ ID NO: 168. In certain embodiments, a scFab comprises a CDRH1 sequence as provided in SEQ ID NO: 106, a CDRH2 sequence as provided in SEQ ID NO: 107 or 121, a CDRH3 sequence as provided in SEQ ID NO: 108, a CDRL1 sequence as provided in SEQ ID NO: 169, a CDRL2 sequence as provided in SEQ ID NO: 170, and a CDRL3 sequence as provided in SEQ ID NO: 171. In certain embodiments, a scFab comprises an amino acid sequence having at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99%, or 100% identity to the amino acid sequence provided in any one of SEQ ID NOs.: 218-219 or 226-227.

“Fv” is a small antibody fragment that contains a complete antigen-recognition and antigen-binding site. This fragment generally consists of a dimer of one heavy- and one light-chain variable region domain in tight, non-covalent association. However, even a single variable domain (or half of an Fv comprising only three CDRs specific for an antigen) has the ability to recognize and bind antigen, although typically at a lower affinity than the entire binding site.

“Single-chain Fv” also abbreviated as “sFv” or “scFv”, are antibody fragments that comprise the V_(H) and V_(L) antibody domains connected into a single polypeptide chain. In some embodiments, the scFv polypeptide comprises a polypeptide linker disposed between and linking the V_(H) and V_(L) domains that enables the scFv to retain or form the desired structure for antigen binding. Such a peptide linker can be incorporated into a fusion polypeptide using standard techniques well known in the art. Additionally or alternatively, Fv can have a disulfide bond formed between and stabilizing the VH and the VL. For a review of scFv, see Pluckthun in The Pharmacology of Monoclonal Antibodies, vol. 113, Rosenburg and Moore eds., Springer-Verlag, New York, pp. 269-315 (1994); Borrebaeck 1995, infra. In certain embodiments, the antibody or antigen-binding fragment comprises a scFv comprising a VH domain, a VL domain, and a peptide linker linking the VH domain to the VL domain. In particular embodiments, a scFv comprises a VH domain linked to a VL domain by a peptide linker, which can be in a VH-linker-VL orientation or in a VL-linker-VH orientation. Any scFv of the present disclosure may be engineered so that the C-terminal end of the VL domain is linked by a short peptide sequence to the N-terminal end of the VH domain, or vice versa (i.e., (N)VL(C)-linker-(N)VH(C) or (N)VH(C)-linker-(N)VL(C). Alternatively, in some embodiments, a linker may be linked to an N-terminal portion or end of the VH domain, the VL domain, or both.

Peptide linker sequences may be chosen, for example, based on: (1) their ability to adopt a flexible extended conformation; (2) their inability or lack of ability to adopt a secondary structure that could interact with functional epitopes on the first and second polypeptides and/or on a target molecule; and/or (3) the lack or relative lack of hydrophobic or charged residues that might react with the polypeptides and/or target molecule. Other considerations regarding linker design (e.g., length) can include the conformation or range of conformations in which the VH and VL can form a functional antigen-binding site. In certain embodiments, peptide linker sequences contain, for example, Gly, Asn and Ser residues. Other near neutral amino acids, such as Thr and Ala, may also be included in a linker sequence. Other amino acid sequences which may be usefully employed as linker include those disclosed in Maratea et al., Gene 40:39 46 (1985); Murphy et al., Proc. Natl. Acad. Sci. USA 83:8258 8262 (1986); U.S. Pat. Nos. 4,935,233, and 4,751,180. Other illustrative and non-limiting examples of linkers may include, for example, Glu-Gly-Lys-Ser-Ser-Gly-Ser-Gly-Ser-Glu-Ser-Lys-Val-Asp (SEQ ID NO: 215) (Chaudhary et al., Proc. Natl. Acad. Sci. USA 87:1066-1070 (1990)) and Lys-Glu-Ser-Gly-Ser-Val-Ser-Ser-Glu-Gln-Leu-Ala-Gln-Phe-Arg-Ser-Leu-Asp (SEQ ID NO: 216) (Bird et al., Science 242:423-426 (1988)) and the pentamer Gly-Gly-Gly-Gly-Ser (SEQ ID NO: 217) when present in a single iteration or repeated 1 to 5 or more times, or more; see, e.g., SEQ ID NO: 213. Any suitable linker may be used, and in general can be about 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 15 23, 24, 25, 26, 27, 28, 29, 30, 40, 50, 60, 70, 80, 90, 100 amino acids in length, or less than about 200 amino acids in length, and will preferably comprise a flexible structure (can provide flexibility and room for conformational movement between two regions, domains, motifs, fragments, or modules connected by the linker), and will preferably be biologically inert and/or have a low risk of immunogenicity in a human. Exemplary linkers include those comprising or consisting of the amino acid sequence set forth in any one or more of SEQ ID NOs: 206-217. In certain embodiments, the linker comprises or consists of an amino acid sequence having at least 75% (i.e., at least about 75%, 80%, 85%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99%, or more) identity to the amino acid sequence set forth in any one of SEQ ID NOs: 206-217.

scFv can be constructed using any combination of the VH and VL sequences or any combination of the CDRH1, CDRH2, CDRH3, CDRL1, CDRL2, and CDRL3 sequences disclosed herein. In certain embodiments, a scFv comprises the VH sequence provided in SEQ ID NO: 105 or SEQ ID NO: 113 and the VL sequence provided in SEQ ID NO: 168. In certain embodiments, a scFab comprises a CDRH1 sequence as provided in SEQ ID NO: 106, a CDRH2 sequence as provided in SEQ ID NO: 107 or 121, a CDRH3 sequence as provided in SEQ ID NO: 108, a CDRL1 sequence as provided in SEQ ID NO: 169, a CDRL2 sequence as provided in SEQ ID NO: 170, and a CDRL3 sequence as provided in SEQ ID NO: 171. In certain embodiments, a scFv can comprise the amino acid sequence as provided in SEQ ID NO: 220-221 or SEQ ID NO: 228-229.

In some embodiments, linker sequences are not required; for example, when the first and second polypeptides have non-essential N-terminal amino acid regions that can be used to separate the functional domains and prevent steric interference.

During antibody development, DNA in the germline variable (V), joining (J), and diversity (D) gene loci may be rearranged and insertions and/or deletions of nucleotides in the coding sequence may occur. Somatic mutations may be encoded by the resultant sequence, and can be identified by reference to a corresponding known germline sequence. In some contexts, somatic mutations that are not critical to a desired property of the antibody (e.g., binding to a SARS-CoV-2 antigen), or that confer an undesirable property upon the antibody (e.g., an increased risk of immunogenicity in a subject administered the antibody), or both, may be replaced by the corresponding germline-encoded amino acid, or by a different amino acid, so that a desirable property of the antibody is improved or maintained and the undesirable property of the antibody is reduced or abrogated. Thus, in some embodiments, the antibody or antigen-binding fragment of the present disclosure comprises at least one more germline-encoded amino acid in a variable region as compared to a parent antibody or antigen-binding fragment, provided that the parent antibody or antigen binding fragment comprises one or more somatic mutations. Variable region and CDR amino acid sequences of exemplary anti-SARS-CoV-2 antibodies of the present disclosure are provided in Table 2 herein.

In certain embodiments, an antibody or antigen-binding fragment comprises an amino acid modification (e.g., a substitution mutation) to remove an undesired risk of oxidation, deamidation, and/or isomerization.

Also provided herein are variant antibodies that comprise one or more amino acid alterations in a variable region (e.g., VH, VL, framework or CDR) as compared to a presently disclosed (“parent”) antibody, wherein the variant antibody is capable of binding to a SARS-CoV-2 antigen.

In certain embodiments, the VH comprises or consists of an amino acid sequence having at least 85% (i.e., 85%, 86, 87, 88, 89, 90, 91, 92, 93, 94, 95, 96, 97, 98, 99, or 100%) identity to the amino acid sequence according to any one of SEQ ID NOs.: 1, 9-15, 23, 24, 27, 28-46, 55, 63, 79, 87, 95, 103, 105, 113-120, 129-146, 155, 172, 176-178, 194, 196, 198, 200, 202, and 239, wherein the variation is optionally limited to one or more framework regions and/or the variation comprises one or more substitution to a germline-encoded amino acid; and/or (ii) the VL comprises or consists of an amino acid sequence having at least 85% (i.e., 85%, 86, 87, 88, 89, 90, 91, 92, 93, 94, 95, 96, 97, 98, 99, or 100%) identity to the amino acid sequence according to any one of SEQ ID NOs.: 5, 47-50, 59, 67, 71-72, 75, 76, 83, 91, 99, 109, 147-150, 159, 168, 182, 190, 234, and 243, wherein the variation is optionally limited to one or more framework regions and/or the variation comprises one or more substitution to a germline-encoded amino acid.

In some embodiments, an antibody or antigen-binding fragment comprises VH and VL amino acid sequences that are encoded by, or that are the same as VH and VL amino acid sequences that are encoded by:

(i) a VH1-18 gene and a VK3-20 gene, respectively, or that are encoded by a polynucleotide having at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, or at least 99% identity to VH1-18 and VK3-20, respectively;

(ii) a VH3-7 allele and a VL3-25 allele, respectively, or that are encoded by a polynucleotide having at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, or at least 99% identity to VH3-7 and VL3-25, respectively;

(iii) a VH3-23 allele and a VK1-5 allele, respectively, or that are encoded by a polynucleotide having at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, or at least 99% identity to VH3-23 and VK1-5, respectively;

(iv) a VH3-13 allele and a VK1-39 allele respectively, or that are encoded by a polynucleotide having at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, or at least 99% identity to VH3-13 and VK1-39, respectively;

(v) a VH1-18 allele and a VK3-11 allele, respectively, or that are encoded by a polynucleotide having at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, or at least 99% identity to VH1-18 and VK3-11, respectively; or

(vi) a VH1-69 allele and a VL2-23 allele, respectively, or that are encoded by a polynucleotide having at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, or at least 99% identity to VH1-69 and VL2-23, respectively.

In certain embodiments, the VH comprises or consists of any VH amino acid sequence set forth in Table 2, and the VL comprises or consists of any VL amino acid sequence set forth in Table 2. In particular embodiments, the VH and the VL comprise or consist of the amino acid sequences according to SEQ ID NOs.: (i) 1 and 5 or 234, respectively; (ii) any one of 9-15 and 5 or 234, respectively; (iii) 23 or 24 and 5 or 234, respectively; (iv) 27 and 5 or 234, respectively; (v) any one of 28-46 and 5 or 234, respectively; (vi) 1 and any one of 47-50, respectively; (vii) any one of 9-15 and any one of 47-50, respectively; (viii) 23 or 24 and any one of 47-50, respectively; (ix) 27 and any one of 47-50, respectively; (x) any one of 28-46 and any one of 47-50, respectively; (xi) 55 and 59, respectively; (xii) 63 and 67, respectively; (xiii) 63 and 71 or 72, respectively; (xiv) 63 and 75 or 76, respectively; (xv) 79 and 83, respectively; (xvi) 87 and 91, respectively; (xvii) 95 and 99, respectively; (xviii) 103 and 99, respectively; (xiv) 105 and 109 or 168, respectively; (xx) any one of 113-120 and 109 or 168, respectively; (xxi) 129 and 109 or 168, respectively; (xxii) any one of 130-146 and 109 or 168, respectively; (xxiii) 105 and any one of 147-150, respectively; (xxiv) any one of 113-120 and any one of 147-150, respectively; (xxv) any one of 130-146 and any one of 147-150, respectively; (xxvi) 155 and 159, respectively; (xxvii) 172 and 168, respectively; (xxviii) 176 or 177 and 5 or any one of 47-50, respectively; (xxix) 178 and 182 or 190, respectively (i.e., 178 and 182, respectively, or 178 and 190, respectively); (xxx) 194 and 182, respectively; (xxxi) 196 and 182, respectively; (xxxii) 198 and 182, respectively; (xxxiii) 200 and 182, respectively; (xxxiv) 202 and 182, respectively; or (xxxv) 239 and 243, respectively.

In certain embodiments, an antigen or an antigen-binding fragment of the present disclosure comprises a VH comprising or consisting of the amino acid sequence according to SEQ ID NO.:79 and a VL comprising or consisting of the amino acid sequence according to SEQ ID NO.:83. In further embodiments, an antigen or an antigen-binding fragment of the present disclosure comprises a VH comprising or consisting of the amino acid sequence according to SEQ ID NO.:79 and a VL comprising or consisting of the amino acid sequence according to SEQ ID NO.:83 and binds to SARS-CoV-2 S protein with a K_(D) of less than about 4.5×10-9 M, less than about 5×10-9 M, less than about 1×10-10 M, less than about 5×10-10 M, less than about 1×10-11 M, less than about 5×10-11 M, less than about 1×10-12 M, or less than about 5×10-12 M. In still further embodiments, an antigen or an antigen-binding fragment of the present disclosure comprises a VH comprising or consisting of the amino acid sequence according to SEQ ID NO: 79 and a VL comprising or consisting of the amino acid sequence according to SEQ ID NO: 83 and is capable of neutralizing a SARS-CoV-2 infection, or a virus pseudotyped with SARS-CoV-2, with an IC50 of about 16 to about 20 μg/ml.

In certain embodiments, an antibody or an antigen-binding fragment of the present disclosure comprises a VH comprising or consisting of the amino acid sequence according to SEQ ID NO.:105 and a VL comprising or consisting of the amino acid sequence according to SEQ ID NO.:168. In further embodiments, an antibody or an antigen-binding fragment of the present disclosure comprises a VH comprising or consisting of the amino acid sequence according to SEQ ID NO.:105 and a VL comprising or consisting of the amino acid sequence according to SEQ ID NO.:168 and binds to SARS-CoV-2 S protein with a K_(D) of less than about 4.5×10-9 M, less than about 5×10-9 M, less than about 1×10-10 M, less than about 5×10-10 M, less than about 1×10-11 M, less than about 5×10-11 M, less than about 1×10-12 M, or less than about 5×10-12 M. In still further embodiments, an antbody or an antigen-binding fragment of the present disclosure comprises a VH comprising or consisting of the amino acid sequence according to SEQ ID NO.:105 and a VL comprising or consisting of the amino acid sequence according to SEQ ID NO.:168 and is capable of neutralizing a SARS-CoV-2 infection, or a virus pseudotyped with SARS-CoV-2, with an IC50 of about 0.3 to about 0.4 μg/ml.

In certain embodiments, an antibody or an antigen-binding fragment of the present disclosure comprises a VH comprising or consisting of the amino acid sequence according to SEQ ID NO.:105 and a VL comprising or consisting of the amino acid sequence according to SEQ ID NO.:168 and binds to SARS-CoV-2 S protein RBD with an EC50 of about 11 to about 25 ng/ml. In certain embodiments, an antibody or an antigen-binding fragment of the present disclosure comprises a VH comprising or consisting of the amino acid sequence according to SEQ ID NO.:113 and a VL comprising or consisting of the amino acid sequence according to SEQ ID NO.:168 and binds to SARS-CoV-2 S protein RBD with an EC50 of about 9 to about 23 ng/ml. In certain embodiments, an antibody or an antigen-binding fragment of the present disclosure comprises a VH comprising or consisting of the amino acid sequence according to SEQ ID NO.:129 and a VL comprising or consisting of the amino acid sequence according to SEQ ID NO.:168 and binds to SARS-CoV-2 S protein RBD with an EC50 of about 8 to about 22 ng/ml. In certain embodiments, an antibody or an antigen-binding fragment of the present disclosure comprises a VH comprising or consisting of the sequence according to SEQ ID NO.:119 and a VL comprising or consisting of the sequence according to SEQ ID NO.:168 and binds to SARS-CoV-2 S protein RBD with an EC50 of about 8 to about 22 ng/ml. In certain embodiments, an antibody or an antigen-binding fragment of the present disclosure comprises a VH comprising or consisting of the amino acid sequence according to SEQ ID NO.:172 and a VL comprising or consisting of the amino acid sequence according to SEQ ID NO.:168 and binds to SARS-CoV-2 S protein RBD with an EC50 of about 7 to about 19 ng/ml.

In certain embodiments, an antibody or antigen-binding fragment of the present disclosure is monospecific (e.g., binds to a single epitope) or is multispecific (e.g., binds to multiple epitopes and/or target molecules). Antibodies and antigen binding fragments may be constructed in various formats. Exemplary antibody formats disclosed in Spiess et al., Mol. Immunol. 67(2):95 (2015), and in Brinkmann and Kontermann, mAbs 9(2):182-212 (2017), which formats and methods of making the same are incorporated herein by reference and include, for example, Bispecific T cell Engagers (BiTEs), DARTs, Knobs-Into-Holes (KIH) assemblies, scFv-CH3-KIH assemblies, KIH Common Light-Chain antibodies, TandAbs, Triple Bodies, TriBi Minibodies, Fab-scFv, scFv-CH-CL-scFv, F(ab′)2-scFv2, tetravalent HCabs, Intrabodies, CrossMabs, Dual Action Fabs (DAFs) (two-in-one or four-in-one), DutaMabs, DT-IgG, Charge Pairs, Fab-arm Exchange, SEEDbodies, Triomabs, LUZ-Y assemblies, Fcabs, κλ-bodies, orthogonal Fabs, DVD-Igs (e.g., U.S. Pat. No. 8,258,268, which formats are incorporated herein by reference in their entirety), IgG(H)-scFv, scFv-(H)IgG, IgG(L)-scFv, scFv-(L)IgG, IgG(L,H)-Fv, IgG(H)-V, V(H)-IgG, IgG(L)-V, V(L)-IgG, KIH IgG-scFab, 2scFv-IgG, IgG-2scFv, scFv4-Ig, Zybody, and DVI-IgG (four-in-one), as well as so-called FIT-Ig (e.g., PCT Publication No. WO 2015/103072, which formats are incorporated herein by reference in their entirety), so-called WuxiBody formats (e.g., PCT Publication No. WO 2019/057122, which formats are incorporated herein by reference in their entirety), and so-called In-Elbow-Insert Ig formats (IEI-Ig; e.g., PCT Publication Nos. WO 2019/024979 and WO 2019/025391, which formats are incorporated herein by reference in their entirety).

In certain embodiments, the antibody or antigen-binding fragment comprises two or more of VH domains, two or more VL domains, or both (i.e., two or more VH domains and two or more VL domains). In particular embodiments, an antigen-binding fragment comprises the format (N-terminal to C-terminal direction) VH-linker-VL-linker-VH-linker-VL, wherein the two VH sequences can be the same or different and the two VL sequences can be the same or different. Such linked scFvs can include any combination of VH and VL domains arranged to bind to a given target, and in formats comprising two or more VH and/or two or more VL, one, two, or more different eptiopes or antigens may be bound. It will be appreciated that formats incorporating multiple antigen-binding domains may include VH and/or VL sequences in any combination or orientation. For example, the antigen-binding fragment can comprise the format VL-linker-VH-linker-VL-linker-VH, VH-linker-VL-linker-VL-linker-VH, or VL-linker-VH-linker-VH-linker-VL.

Monospecific or multispecific antibodies or antigen-binding fragments of the present disclosure can comprise any combination of the VH and VL sequences and/or any combination of the CDRH1, CDRH2, CDRH3, CDRL1, CDRL2, and CDRL3 sequences disclosed herein. In certain embodiments, an antibody or antigen-binding fragment comprises the VH sequence provided in SEQ ID NO.:105 or SEQ ID NO.:113 and the VL sequence provided in SEQ ID NO: 168. In certain embodiments, an antibody or antigen-binding fragment comprises a CDRH1 sequence as provided in SEQ ID NO.:106, a CDRH2 sequence as provided in SEQ ID NO.:107 or 121, a CDRH3 sequence as provided in SEQ ID NO.:108, a CDRL1 sequence as provided in SEQ ID NO.:169, a CDRL2 sequence as provided in SEQ ID NO.:170, and a CDRL3 sequence as provided in SEQ ID NO.:171. In certain embodiments, an antibody or antigen-binding fragment comprises the amino acid sequence as provided in any one of SEQ ID NOs.: 222-225 or 230-233. A bispecific or multispecific antibody or antigen-binding fragment may, in some embodiments, comprise one, two, or more antigen-binding domains (e.g., a VH and a VL) of the instant disclosure. Two or more binding domains may be present that bind to the same or a different SARS-CoV-2 epitope, and a bispecific or multispecific antibody or antigen-binding fragment as provided herein can, in some embodiments, comprise a further SARS-CoV-2 binding domain, and/or can comprise a binding domain that binds to a different antigen or pathogen altogether.

In any of the presently disclosed embodiments, the antibody or antigen-binding fragment can be multispecific; e.g., bispecific, trispecific, or the like.

In certain embodiments, the antibody or antigen-binding fragment comprises: (i) a first VH and a first VL; and (ii) a second VH and a second VL, wherein the first VH and the second VH are different and each independently comprise an amino acid sequence having at least 85% (i.e., 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99%, or 100%) identity to the amino acid sequence set forth in any one of SEQ ID NOs.: 1, 9-15, 23, 24, 27-46, 55, 63, 79, 87, 95, 103, 105, 113-120, 129-146, 155, 172, 176-178, 194, 196, 198, 200, 202, and 239, and wherein the first VL and the second VL are different and each independently comprise an amino acid sequence having at least 85% (i.e., 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99%, or 100%) identity to the amino acid sequence set forth in any one of SEQ ID NOs.: 5, 47-50, 59, 67, 71, 72, 75, 76, 83, 91, 99, 109, 147-150, 159, 168, 182, 190, 234, and 243, and wherein the first VH and the first VL together form a first antigen-binding site, and wherein the second VH and the second VL together form a second antigen-binding site.

In certain embodiments, the antibody or antigen-binding fragment comprises a Fc polypeptide, or a fragment thereof. The “Fc” comprises the carboxy-terminal portions (i.e., the CH2 and CH3 domains of IgG) of both antibody H chains held together by disulfides. Antibody “effector functions” refer to those biological activities attributable to the Fc region (a native sequence Fc region or amino acid sequence variant Fc region) of an antibody, and vary with the antibody isotype. Examples of antibody effector functions include: C1q binding and complement dependent cytotoxicity; Fc receptor binding; antibody-dependent cell-mediated cytotoxicity (ADCC); phagocytosis; down regulation of cell surface receptors (e.g., B cell receptor); and B cell activation. As discussed herein, modifications (e.g., amino acid substitutions) may be made to an Fc domain in order to modify (e.g., improve, reduce, or ablate) one or more functionality of an Fc-containing polypeptide (e.g., an antibody of the present disclosure). Such functions include, for example, Fc receptor (FcR) binding, antibody half-life modulation (e.g., by binding to FcRn), ADCC function, protein A binding, protein G binding, and complement binding. Amino acid modifications that modify (e.g., improve, reduce, or ablate) Fc functionalities include, for example, the T250Q/M428L, M252Y/S254T/T256E, H433K/N434F, M428L/N434S, E233P/L234V/L235A/G236+A327G/A330S/P331S, E333A, S239D/A330L/I332E, P257I/Q311, K326W/E333S, S239D/I332E/G236A, N297Q, K322A, S228P, L235E+E318A/K320A/K322A, L234A/L235A (also referred to herein as “LALA”), and L234A/L235A/P329G mutations, which mutations are summarized and annotated in “Engineered Fc Regions”, published by InvivoGen (2011) and available online at invivogen.com/PDF/review/review-Engineered-Fc-Regions-invivogen.pdf?utm_source=review&utm_medium=pdf&utm_campaign=review&utm_content=Engineered-Fc-Regions, and are incorporated herein by reference. Unless the context indicates otherwise, Fc amino acid residues are numbered herein according to the EU numbering system.

For example, to activate the complement cascade, the C1q protein complex can bind to at least two molecules of IgG1 or one molecule of IgM when the immunoglobulin molecule(s) is attached to the antigenic target (Ward, E. S., and Ghetie, V., Ther. Immunol. 2 (1995) 77-94). Burton, D. R., described (Mol. Immunol. 22 (1985) 161-206) that the heavy chain region comprising amino acid residues 318 to 337 is involved in complement fixation. Duncan, A. R., and Winter, G. (Nature 332 (1988) 738-740), using site directed mutagenesis, reported that Glu318, Lys320 and Lys322 form the binding site to C1q. The role of Glu318, Lys320 and Lys 322 residues in the binding of C1q was confirmed by the ability of a short synthetic peptide containing these residues to inhibit complement mediated lysis.

For example, FcR binding can be mediated by the interaction of the Fc moiety (of an antibody) with Fc receptors (FcRs), which are specialized cell surface receptors on cells including hematopoietic cells. Fc receptors belong to the immunoglobulin superfamily, and shown to mediate both the removal of antibody-coated pathogens by phagocytosis of immune complexes, and the lysis of erythrocytes and various other cellular targets (e.g. tumor cells) coated with the corresponding antibody, via antibody dependent cell mediated cytotoxicity (ADCC; Van de Winkel, J. G., and Anderson, C. L., J. Leukoc. Biol. 49 (1991) 511-524). FcRs are defined by their specificity for immunoglobulin classes; Fc receptors for IgG antibodies are referred to as FcγR, for IgE as FcεR, for IgA as FcαR and so on and neonatal Fc receptors are referred to as FcRn. Fc receptor binding is described for example in Ravetch, J. V., and Kinet, J. P., Annu. Rev. Immunol. 9 (1991) 457-492; Capel, P. J., et al., Immunomethods 4 (1994) 25-34; de Haas, M., et al., J. Lab. Clin. Med. 126 (1995) 330-341; and Gessner, J. E., et al., Ann. Hematol. 76 (1998) 231-248.

Cross-linking of receptors by the Fc domain of native IgG antibodies (FcγR) triggers a wide variety of effector functions including phagocytosis, antibody-dependent cellular cytotoxicity, and release of inflammatory mediators, as well as immune complex clearance and regulation of antibody production. Fc moieties providing cross-linking of receptors (e.g., FcγR) are contemplated herein. In humans, three classes of FcγR have been characterized to-date, which are: (i) FcγRI (CD64), which binds monomeric IgG with high affinity and is expressed on macrophages, monocytes, neutrophils and eosinophils; (ii) FcγRII (CD32), which binds complexed IgG with medium to low affinity, is widely expressed, in particular on leukocytes, is believed to be a central player in antibody-mediated immunity, and which can be divided into FcγRIIA, FcγRIIB and FcγRIIC, which perform different functions in the immune system, but bind with similar low affinity to the IgG-Fc, and the ectodomains of these receptors are highly homologuous; and (iii) FcγRIII (CD16), which binds IgG with medium to low affinity and has been found in two forms: FcγRIIIA, which has been found on NK cells, macrophages, eosinophils, and some monocytes and T cells, and is believed to mediate ADCC; and FcγRIIIB, which is highly expressed on neutrophils.

FcγRIIA is found on many cells involved in killing (e.g. macrophages, monocytes, neutrophils) and seems able to activate the killing process. FcγRIIB seems to play a role in inhibitory processes and is found on B-cells, macrophages and on mast cells and eosinophils. Importantly, it has been shown that 75% of all FcγRIIB is found in the liver (Ganesan, L. P. et al., 2012: “FcγRIIb on liver sinusoidal endothelium clears small immune complexes,” Journal of Immunology 189: 4981-4988). FcγRIIB is abundantly expressed on Liver Sinusoidal Endothelium, called LSEC, and in Kupffer cells in the liver and LSEC are the major site of small immune complexes clearance (Ganesan, L. P. et al., 2012: FcγRIIb on liver sinusoidal endothelium clears small immune complexes. Journal of Immunology 189: 4981-4988).

In some embodiments, the antibodies disclosed herein and the antigen-binding fragments thereof comprise an Fc polypeptide or fragment thereof for binding to FcγRIIb, in particular an Fc region, such as, for example IgG-type antibodies. Moreover, it is possible to engineer the Fc moiety to enhance FcγRIIB binding by introducing the mutations S267E and L328F as described by Chu, S. Y. et al., 2008: Inhibition of B cell receptor-mediated activation of primary human B cells by coengagement of CD19 and FcgammaRIIb with Fc-engineered antibodies. Molecular Immunology 45,3926-3933. Thereby, the clearance of immune complexes can be enhanced (Chu, S., et al., 2014: Accelerated Clearance of IgE In Chimpanzees Is Mediated By Xmab7195, An Fc-Engineered Antibody With Enhanced Affinity For Inhibitory Receptor FcγRIIb. Am J Respir Crit, American Thoracic Society International Conference Abstracts). In some embodiments, the antibodies of the present disclosure, or the antigen binding fragments thereof, comprise an engineered Fc moiety with the mutations S267E and L328F, in particular as described by Chu, S. Y. et al., 2008: Inhibition of B cell receptor-mediated activation of primary human B cells by coengagement of CD19 and FcgammaRIIb with Fc-engineered antibodies. Molecular Immunology 45, 3926-3933.

On B cells, FcγRIIB may function to suppress further immunoglobulin production and isotype switching to, for example, the IgE class. On macrophages, FcγRIIB is thought to inhibit phagocytosis as mediated through FcγRIIA. On eosinophils and mast cells, the B form may help to suppress activation of these cells through IgE binding to its separate receptor.

Regarding FcγRI binding, modification in native IgG of at least one of E233-G236, P238, D265, N297, A327 and P329 reduces binding to FcγRI. IgG2 residues at positions 233-236, substituted into corresponding positions IgG1 and IgG4, reduces binding of IgG1 and IgG4 to FcγRI by 10³-fold and eliminated the human monocyte response to antibody-sensitized red blood cells (Armour, K. L., et al. Eur. J. Immunol. 29 (1999) 2613-2624).

Regarding FcγRII binding, reduced binding for FcγRIIA is found, e.g., for IgG mutation of at least one of E233-G236, P238, D265, N297, A327, P329, D270, Q295, A327, R292 and K414.

Two allelic forms of human FcγRIIA are the “H131” variant, which binds to IgG1 Fc with high affinity, and the “R131” variant, which binds to IgG1 Fc with low affinity. See, e.g., Bruhns et al., Blood 113:3716-3725 (2009).

Regarding FcγRIII binding, reduced binding to FcγRIIIA is found, e.g., for mutation of at least one of E233-G236, P238, D265, N297, A327, P329, D270, Q295, A327, S239, E269, E293, Y296, V303, A327, K338 and D376. Mapping of the binding sites on human IgG1 for Fc receptors, the above-mentioned mutation sites, and methods for measuring binding to FcγRI and FcγRIIA, are described in Shields, R. L., et al., J. Biol. Chem. 276 (2001) 6591-6604.

Two allelic forms of human FcγRIIIA are the “F158” variant, which binds to IgG1 Fc with low affinity, and the “V158” variant, which binds to IgG1 Fc with high affinity. See, e.g., Bruhns et al., Blood 113:3716-3725 (2009).

Regarding binding to FcγRII, two regions of native IgG Fc appear to be involved in interactions between FcγRIIs and IgGs, namely (i) the lower hinge site of IgG Fc, in particular amino acid residues L, L, G, G (234-237, EU numbering), and (ii) the adjacent region of the CH2 domain of IgG Fc, in particular a loop and strands in the upper CH2 domain adjacent to the lower hinge region, e.g. in a region of P331 (Wines, B. D., et al., J. Immunol. 2000; 164: 5313-5318). Moreover, FcγRT appears to bind to the same site on IgG Fc, whereas FcRn and Protein A bind to a different site on IgG Fc, which appears to be at the CH2-CH3 interface (Wines, B. D., et al., J. Immunol. 2000; 164: 5313-5318).

Also contemplated are mutations that increase binding affinity of an Fc polypeptide or fragment thereof of the present disclosure to a (i.e., one or more) Fcγ receptor (e.g., as compared to a reference Fc polypeptide or fragment thereof or containing the same that does not comprise the mutation(s); e.g., a wild-type Fc polypeptide or fragment thereof (e.g., of the same isotype as the Fc polypeptide or fragment thereof that comprises the mutation or mutations) or a Fc polypeptide or fragment thereof that is otherwise identical or is substantially identical to the Fc polypeptide or fragment thereof that comprises the mutation or mutations). See, e.g., Delillo and Ravetch, Cell 161(5):1035-1045 (2015) and Ahmed et al., J. Struc. Biol. 194(1):78 (2016), the Fc mutations and techniques of which are incorporated herein by reference.

In any of the herein disclosed embodiments, an antibody or antigen-binding fragment can comprise a Fc polypeptide or fragment thereof comprising a mutation selected from G236A; S239D; A330L; and I332E; or a combination comprising any two or more of the same; e.g., S239D/I332E; S239D/A330L/I332E; G236A/S239D/I332E; G236A/A330L/I332E (also referred to herein as “GAALIE”); or G236A/S239D/A330L/I332E. In some embodiments, the Fc polypeptide or fragment thereof does not comprise S239D. In some embodiments, the Fc polypeptide or fragment thereof comprises S at position 239.

In certain embodiments, the Fc polypeptide or fragment thereof may comprise or consist of at least a portion of an Fc polypeptide or fragment thereof that is involved in binding to FcRn binding. In certain embodiments, the Fc polypeptide or fragment thereof comprises one or more amino acid modifications that improve binding affinity for (e.g., enhance binding to) FcRn (e.g., at a pH of about 6.0) and, in some embodiments, thereby extend in vivo half-life of a molecule comprising the Fc polypeptide or fragment thereof (e.g., as compared to a reference (e.g., wild-type) Fc polypeptide or fragment thereof or antibody that is otherwise the same but does not comprise the modification(s)). In certain embodiments, the Fc polypeptide or fragment thereof comprises or is derived from a IgG Fc and a half-life-extending mutation comprises any one or more of: M428L; N434S; N434H; N434A; N434S; M252Y; S254T; T256E; T250Q; P257I Q311I; D376V; T307A; E380A (EU numbering). In certain embodiments, a half-life-extending mutation comprises M428L/N434S (also referred to herein as “MLNS” or “LS”). In certain embodiments, a half-life-extending mutation comprises M252Y/S254T/T256E. In certain embodiments, a half-life-extending mutation comprises T250Q/M428L. In certain embodiments, a half-life-extending mutation comprises P257I/Q311I. In certain embodiments, a half-life-extending mutation comprises P257I/N434H. In certain embodiments, a half-life-extending mutation comprises D376V/N434H. In certain embodiments, a half-life-extending mutation comprises T307A/E380A/N434A.

In some embodiments, an antibody or antigen-binding fragment includes a Fc moiety that comprises the substitution mutations M428L/N434S. In some embodiments, an antibody or antigen-binding fragment includes a Fc polypeptide or fragment thereof that comprises the substitution mutations G236A/A330L/I332E. In certain embodiments, an antibody or antigen-binding fragment includes a (e.g., IgG) Fc moiety that comprises a G236A mutation, an A330L mutation, and a I332E mutation (GAALIE), and does not comprise a S239D mutation (e.g., comprises a native S at position 239). In particular embodiments, an antibody or antigen-binding fragment includes an Fc polypeptide or fragment thereof that comprises the substitution mutations: M428L/N434S and G236A/A330L/I332E, and optionally does not comprise S239D. In certain embodiments, an antibody or antigen-binding fragment includes a Fc polypeptide or fragment thereof that comprises the substitution mutations: M428L/N434S and G236A/S239D/A330L/I332E.

In certain embodiments, the antibody or antigen-binding fragment comprises a mutation that alters glycosylation, wherein the mutation that alters glycosylation comprises N297A, N297Q, or N297G, and/or the antibody or antigen-binding fragment is partially or fully aglycosylated and/or is partially or fully afucosylated. Host cell lines and methods of making partially or fully aglycosylated or partially or fully afucosylated antibodies and antigen-binding fragments are known (see, e.g., PCT Publication No. WO 2016/181357; Suzuki et al. Clin. Cancer Res. 13(6):1875-82 (2007); Huang et al. MAbs 6:1-12 (2018)).

In certain embodiments, the antibody or antigen-binding fragment is capable of eliciting continued protection in vivo in a subject even once no detectable levels of the antibody or antigen-binding fragment can be found in the subject (i.e., when the antibody or antigen-binding fragment has been cleared from the subject following administration). Such protection is referred to herein as a vaccinal effect. Without wishing to be bound by theory, it is believed that dendritic cells can internalize complexes of antibody and antigen and thereafter induce or contribute to an endogenous immune response against antigen. In certain embodiments, an antibody or antigen-binding fragment comprises one or more modifications, such as, for example, mutations in the Fc comprising G236A, A330L, and I332E, that are capable of activating dendritic cells that may induce, e.g., T cell immunity to the antigen.

In any of the presently disclosed embodiments, the antibody or antigen-binding fragment comprises a Fc polypeptide or a fragment thereof, including a CH2 (or a fragment thereof, a CH3 (or a fragment thereof), or a CH2 and a CH3, wherein the CH2, the CH3, or both can be of any isotype and may contain amino acid substitutions or other modifications as compared to a corresponding wild-type CH2 or CH3, respectively. In certain embodiments, a Fc polypeptide of the present disclosure comprises two CH2-CH3 polypeptides that associate to form a dimer.

In any of the presently disclosed embodiments, the antibody or antigen-binding fragment can be monoclonal. The term “monoclonal antibody” (mAb) as used herein refers to an antibody obtained from a population of substantially homogeneous antibodies, i.e., individual antibodies comprising the population are identical except for possible naturally occurring mutations that may be present, in some cases in minor amounts. Monoclonal antibodies are highly specific, being directed against a single antigenic site. Furthermore, in contrast to polyclonal antibody preparations that include different antibodies directed against different epitopes, each monoclonal antibody is directed against a single epitope of the antigen. In addition to their specificity, the monoclonal antibodies are advantageous in that they may be synthesized uncontaminated by other antibodies. The term “monoclonal” is not to be construed as requiring production of the antibody by any particular method. For example, monoclonal antibodies useful in the present invention may be prepared by the hybridoma methodology first described by Kohler et al., Nature 256:495 (1975), or may be made using recombinant DNA methods in bacterial, eukaryotic animal, or plant cells (see, e.g., U.S. Pat. No. 4,816,567). Monoclonal antibodies may also be isolated from phage antibody libraries using the techniques described in Clackson et al., Nature, 352:624-628 (1991) and Marks et al., J. Mol. Biol., 222:581-597 (1991), for example. Monoclonal antibodies may also be obtained using methods disclosed in PCT Publication No. WO 2004/076677A2.

Antibodies and antigen-binding fragments of the present disclosure include “chimeric antibodies” in which a portion of the heavy and/or light chain is identical with or homologous to corresponding sequences in antibodies derived from a particular species or belonging to a particular antibody class or subclass, while the remainder of the chain(s) is identical with or homologous to corresponding sequences in antibodies derived from another species or belonging to another antibody class or subclass, as well as fragments of such antibodies, so long as they exhibit the desired biological activity (see, U.S. Pat. Nos. 4,816,567; 5,530,101 and 7,498,415; and Morrison et al., Proc. Natl. Acad. Sci. USA, 81:6851-6855 (1984)). For example, chimeric antibodies may comprise human and non-human residues. Furthermore, chimeric antibodies may comprise residues that are not found in the recipient antibody or in the donor antibody. These modifications are made to further refine antibody performance. For further details, see Jones et al., Nature 321:522-525 (1986); Riechmann et al., Nature 332:323-329 (1988); and Presta, Curr. Op. Struct. Biol. 2:593-596 (1992). Chimeric antibodies also include primatized and humanized antibodies.

A “humanized antibody” is generally considered to be a human antibody that has one or more amino acid residues introduced into it from a source that is non-human. These non-human amino acid residues are typically taken from a variable domain. Humanization may be performed following the method of Winter and co-workers (Jones et al., Nature, 321:522-525 (1986); Reichmann et al., Nature, 332:323-327 (1988); Verhoeyen et al., Science, 239:1534-1536 (1988)), by substituting non-human variable sequences for the corresponding sequences of a human antibody. Accordingly, such “humanized” antibodies are chimeric antibodies (U.S. Pat. Nos. 4,816,567; 5,530,101 and 7,498,415) wherein substantially less than an intact human variable domain has been substituted by the corresponding sequence from a non-human species. In some instances, a “humanized” antibody is one which is produced by a non-human cell or animal and comprises human sequences, e.g., Hc domains.

A “human antibody” is an antibody containing only sequences that are present in an antibody that is produced by a human. However, as used herein, human antibodies may comprise residues or modifications not found in a naturally occurring human antibody (e.g., an antibody that is isolated from a human), including those modifications and variant sequences described herein. These are typically made to further refine or enhance antibody performance. In some instances, human antibodies are produced by transgenic animals. For example, see U.S. Pat. Nos. 5,770,429; 6,596,541 and 7,049,426.

In certain embodiments, an antibody or antigen-binding fragment of the present disclosure is chimeric, humanized, or human.

Polynucleotides, Vectors, and Host Cells

In another aspect, the present disclosure provides isolated polynucleotides that encode any of the presently disclosed antibodies or an antigen-binding fragment thereof, or a portion thereof (e.g., a CDR, a VH, a VL, a heavy chain, or a light chain). In certain embodiments, the polynucleotide is codon-optimized for expression in a host cell. Once a coding sequence is known or identified, codon optimization can be performed using known techniques and tools, e.g., using the GenScript® OptimiumGene™ tool or Gene Synthesis by GeneArt® (ThermoFisher); see also Scholten et al., Clin. Immunol. 119:135, 2006). Codon-optimized sequences include sequences that are partially codon-optimized (i.e., one or a plurality of codons is optimized for expression in the host cell) and those that are fully codon-optimized.

It will also be appreciated that polynucleotides encoding antibodies and antigen-binding fragments of the present disclosure may possess different nucleotide sequences while still encoding a same antibody or antigen-binding fragment due to, for example, the degeneracy of the genetic code, splicing, and the like.

In certain embodiments, the polynucleotide comprises a polynucleotide having at least 50% (i.e., 50%, 55%, 60%, 65%, 70%, 75%, 80%, 85%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99%, or 100%) identity to the polynucleotide sequence according to any one or more of SEQ ID NOs.:186-189, 191-192, 238, 247, 248-250, 254-255, and 257-262.

It will be appreciated that in certain embodiments, a polynucleotide encoding an antibody or antigen-binding fragment is comprised in a polynucleotide that includes other sequences and/or features for, e.g., expression of the antibody or antigen-binding fragment in a host cell. Exemplary features include a promoter sequence, a polyadenylation sequence, a sequence that encodes a signal peptide (e.g., located at the N-terminus of a expressed antibody heavy chain or light chain), or the like. Accordingly, in some embodiments, a polynucleotide further comprises a polynucleotide sequence having at least 50% identity to, comprising, or consisting of the polynucleotide sequence set forth in any one of SEQ ID NOs.:251-253 and 263. In some embodiments, a polynucleotide comprises a sequence that encodes a signal peptide (also referred-to as a leader sequence) having at least 90% to, comprising, or consisting of the amino acid sequence set forth in SEQ ID NO.: 256 or SEQ ID NO.: 264.

In any of the presently disclosed embodiments, the polynucleotide can comprise deoxyribonucleic acid (DNA) or ribonucleic acid (RNA). In some embodiments, the RNA comprises messenger RNA (mRNA).

Vectors are also provided, wherein the vectors comprise or contain a polynucleotide as disclosed herein (e.g., a polynucleotide that encodes an antibody or antigen-binding fragment that binds to SARS-CoV-2). A vector can comprise any one or more of the vectors disclosed herein. In particular embodiments, a vector is provided that comprises a DNA plasmid construct encoding the antibody or antigen-binding fragment, or a portion thereof (e.g., so-called “DMAb”; see, e.g., Muthumani et al., J Infect Dis. 214(3):369-378 (2016); Muthumani et al., Hum Vaccin Immunother 9:2253-2262 (2013)); Flingai et al., Sci Rep. 5:12616 (2015); and Elliott et al., NPJ Vaccines 18 (2017), which antibody-coding DNA constructs and related methods of use, including administration of the same, are incorporated herein by reference). In certain embodiments, a DNA plasmid construct comprises a single open reading frame encoding a heavy chain and a light chain (or a VH and a VL) of the antibody or antigen-binding fragment, wherein the sequence encoding the heavy chain and the sequence encoding the light chain are optionally separated by polynucleotide encoding a protease cleavage site and/or by a polynucleotide encoding a self-cleaving peptide. In some embodiments, the substituent components of the antibody or antigen-binding fragment are encoded by a polynucleotide comprised in a single plasmid. In other embodiments, the substituent components of the antibody or antigen-binding fragment are encoded by a polynucleotide comprised in two or more plasmids (e.g., a first plasmid comprises a polynucleotide encoding a heavy chain, VH, or VH+CH, and a second plasmid comprises a polynucleotide encoding the cognate light chain, VL, or VL+CL). In certain embodiments, a single plasmid comprises a polynucleotide encoding a heavy chain and/or a light chain from two or more antibodies or antigen-binding fragments of the present disclosure. An exemplary expression vector is pVax1, available from Invitrogen®. A DNA plasmid of the present disclosure can be delivered to a subject by, for example, electroporation (e.g., intramuscular electroporation), or with an appropriate formulation (e.g., hyaluronidase). In some embodiments, a vector of the present disclosure comprises a nucleotide sequence encoding a signal peptide. The signal peptide may or may not be present (e.g., can be enzymatically cleaved from) on the mature antibody or antigen-binding fragment. In certain embodiments, the signal peptide is encoded by a nucleotide sequence as set forth in SEQ ID NO.: 252 or SEQ ID NO.: 263, and/or the signal peptide comprises or consists of the amino acid sequence set forth in SEQ ID NO.:256 or SEQ ID NO.: 264. In some embodiments, a vector of the present disclosure comprises a polyadenylation signal sequence. In certain embodiments, the polyadenylation signal sequence comprises or consists of the nucleotide sequence as set forth in SEQ ID NO.: 253.

In some embodiments, a vector of the present disclosure comprises a CMV promoter. In certain embodiments, the promoter comprises or consists of the nucleotide sequence as set forth in SEQ ID NO.: 251.

In a further aspect, the present disclosure also provides a host cell expressing an antibody or antigen-binding fragment according to the present disclosure; or comprising or containing a vector or polynucleotide according the present disclosure.

Examples of such cells include but are not limited to, eukaryotic cells, e.g., yeast cells, animal cells, insect cells, plant cells; and prokaryotic cells, including E. coli. In some embodiments, the cells are mammalian cells. In certain such embodiments, the cells are a mammalian cell line such as CHO cells (e.g., DHFR-CHO cells (Urlaub et al., PNAS 77:4216 (1980)), human embryonic kidney cells (e.g., HEK293T cells), PER.C6 cells, Y0 cells, Sp2/0 cells. NS0 cells, human liver cells, e.g. Hepa RG cells, myeloma cells or hybridoma cells. Other examples of mammalian host cell lines include mouse sertoli cells (e.g., TM4 cells); monkey kidney CV1 line transformed by SV40 (COS-7); baby hamster kidney cells (BHK); African green monkey kidney cells (VERO-76); monkey kidney cells (CV1); human cervical carcinoma cells (HELA); human lung cells (W138); human liver cells (Hep G2); canine kidney cells (MDCK; buffalo rat liver cells (BRL 3A); mouse mammary tumor (MMT 060562); TRI cells; MRC 5 cells; and FS4 cells. Mammalian host cell lines suitable for antibody production also include those described in, for example, Yazaki and Wu, Methods in Molecular Biology, Vol. 248 (B. K. C. Lo, ed., Humana Press, Totowa, N.J.), pp. 255-268 (2003).

In certain embodiments, a host cell is a prokaryotic cell, such as an E. coli. The expression of peptides in prokaryotic cells such as E. coli is well established (see, e.g., Pluckthun, A. Bio/Technology 9:545-551 (1991). For example, antibodies may be produced in bacteria, in particular when glycosylation and Fc effector function are not needed. For expression of antibody fragments and polypeptides in bacteria, see, e.g., U.S. Pat. Nos. 5,648,237; 5,789,199; and 5,840,523.

In particular embodiments, the cell may be transfected with a vector according to the present description with an expression vector. The term “transfection” refers to the introduction of nucleic acid molecules, such as DNA or RNA (e.g. mRNA) molecules, into cells, such as into eukaryotic cells. In the context of the present description, the term “transfection” encompasses any method known to the skilled person for introducing nucleic acid molecules into cells, such as into eukaryotic cells, including into mammalian cells. Such methods encompass, for example, electroporation, lipofection, e.g., based on cationic lipids and/or liposomes, calcium phosphate precipitation, nanoparticle based transfection, virus based transfection, or transfection based on cationic polymers, such as DEAE-dextran or polyethylenimine, etc. In certain embodiments, the introduction is non-viral.

Moreover, host cells of the present disclosure may be transfected stably or transiently with a vector according to the present disclosure, e.g. for expressing an antibody, or an antigen-binding fragment thereof, according to the present disclosure. In such embodiments, the cells may be stably transfected with the vector as described herein. Alternatively, cells may be transiently transfected with a vector according to the present disclosure encoding an antibody or antigen-binding fragment as disclosed herein. In any of the presently disclosed embodiments, a polynucleotide may be heterologous to the host cell.

Accordingly, the present disclosure also provides recombinant host cells that heterologously express an antibody or antigen-binding fragment of the present disclosure. For example, the cell may be of a species that is different to the species from which the antibody was fully or partially obtained (e.g., CHO cells expressing a human antibody or an engineered human antibody). In some embodiments, the cell type of the host cell does not express the antibody or antigen-binding fragment in nature. Moreover, the host cell may impart a post-translational modification (PTM; e.g., glysocylation or fucosylation) on the antibody or antigen-binding fragment that is not present in a native state of the antibody or antigen-binding fragment (or in a native state of a parent antibody from which the antibody or antigen binding fragment was engineered or derived). Such a PTM may result in a functional difference (e.g., reduced immunogenicity). Accordingly, an antibody or antigen-binding fragment of the present disclosure that is produced by a host cell as disclosed herein may include one or more post-translational modification that is distinct from the antibody (or parent antibody) in its native state (e.g., a human antibody produced by a CHO cell can comprise a more post-translational modification that is distinct from the antibody when isolated from the human and/or produced by the native human B cell or plasma cell).

Insect cells useful expressing a binding protein of the present disclosure are known in the art and include, for example, Spodoptera frugipera Sf9 cells, Trichoplusia ni BTI-TN5B1-4 cells, and Spodoptera frugipera SfSWT01^(Mimic™) cells. See, e.g., Palmberger et al., J. Biotechnol. 153(3-4):160-166 (2011). Numerous baculoviral strains have been identified which may be used in conjunction with insect cells, particularly for transfection of Spodoptera frugiperda cells.

Eukaryotic microbes such as filamentous fungi or yeast are also suitable hosts for cloning or expressing protein-encoding vectors, and include fungi and yeast strains with “humanized” glycosylation pathways, resulting in the production of an antibody with a partially or fully human glycosylation pattern. See Gerngross, Nat. Biotech. 22:1409-1414 (2004); Li et al., Nat. Biotech. 24:210-215 (2006).

Plant cells can also be utilized as hosts for expressing a binding protein of the present disclosure. For example, PLANTIBODIES™ technology (described in, for example, U.S. Pat. Nos. 5,959,177; 6,040,498; 6,420,548; 7,125,978; and 6,417,429) employs transgenic plants to produce antibodies.

In certain embodiments, the host cell comprises a mammalian cell. In particular embodiments, the host cell is a CHO cell, a HEK293 cell, a PER.C6 cell, a Y0 cell, a Sp2/0 cell, a NS0 cell, a human liver cell, a myeloma cell, or a hybridoma cell.

In a related aspect, the present disclosure provides methods for producing an antibody, or antigen-binding fragment, wherein the methods comprise culturing a host cell of the present disclosure under conditions and for a time sufficient to produce the antibody, or the antigen-binding fragment. Methods useful for isolating and purifying recombinantly produced antibodies, by way of example, may include obtaining supernatants from suitable host cell/vector systems that secrete the recombinant antibody into culture media and then concentrating the media using a commercially available filter. Following concentration, the concentrate may be applied to a single suitable purification matrix or to a series of suitable matrices, such as an affinity matrix or an ion exchange resin. One or more reverse phase HPLC steps may be employed to further purify a recombinant polypeptide. These purification methods may also be employed when isolating an immunogen from its natural environment. Methods for large scale production of one or more of the isolated/recombinant antibody described herein include batch cell culture, which is monitored and controlled to maintain appropriate culture conditions. Purification of soluble antibodies may be performed according to methods described herein and known in the art and that comport with laws and guidelines of domestic and foreign regulatory agencies.

Compositions

Also provided herein are compositions that comprise any one or more of the presently disclosed antibodies, antigen-binding fragments, polynucleotides, vectors, or host cells, singly or in any combination, and can further comprise a pharmaceutically acceptable carrier, excipient, or diluent. Carriers, excipients, and diluents are discussed in further detail herein.

In certain embodiments, a composition comprises a plurality of an antibody and/or an antigen-binding fragment of the present disclosure, wherein one or more antibody or antigen-binding fragment does not comprise a lysine residue at the C-terminal end of the heavy chain, CH1-CH3, or Fc polypeptide, and wherein one or more antibody or antigen-binding fragment comprises a lysine residue at the C-terminal end of the heavy chain, CH1-CH3, or Fc polypeptide. In some embodiments, a composition comprises an antibody or an antigen-binding fragment thereof that comprises the amino acid sequence set forth in SEQ ID NO.:173, SEQ ID NO.:175, SEQ ID NO.:265, or SEQ ID NO.:266.

In certain embodiments, a composition comprises two or more different antibodies or antigen-binding fragments according to the present disclosure. In certain embodiments, antibodies or antigen-binding fragments to be used in a combination each independently have one or more of the following characteristics: neutralize naturally occurring SARS-CoV-2 variants; do not compete with one another for Spike protein binding; bind distinct Spike protein epitopes; have a reduced formation of resistance to SARS-CoV-2; when in a combination, have a reduced formation of resistance to SARS-CoV-2; potently neutralize live SARS-CoV-2 virus; exhibit additive or synergistic effects on neutralization of live SARS-CoV-2 virus when used in combination; exhibit effector functions; are protective in relevant animal model(s) of infection; are capable of being produced in sufficient quantities for large-scale production.

In certain embodiments, a composition comprises a first antibody or antigen-binding fragment, comprising a VH comprising or consisting of the amino acid sequence as set forth in SEQ ID NO.: 79 and a VL comprising or consisting of the amino acid sequence as set forth in SEQ ID NO.: 83; and a second antibody or antigen-binding fragment comprising, a VH comprising or consisting of the amino acid sequence as set forth in SEQ ID NO.: 105 and a VL comprising of consisting of the amino acid sequence as set forth in SEQ ID NO.: 168. In certain embodiments, a composition comprises a first antibody or antigen-binding fragment comprising a heavy chain variable domain (VH) comprising a CDRH1, a CDRH2, and a CDRH3, and a light chain variable domain (VL) comprising a CDRL1, a CDRL2, and a CDRL3, wherein the CDRH1, CDRH2, and CDRH3 comprise or consist of the amino acid sequences set forth in SEQ ID NOs.: 80-82, respectively, and the CDRL1, CDRL2, and CDRL3 comprise or consist of the amino acid sequences set forth in SEQ ID NOs.: 84-86, respectively, and a second antibody or antigen-binding fragment comprising a heavy chain variable domain (VH) comprising a CDRH1, a CDRH2, and a CDRH3, and a light chain variable domain (VL) comprising a CDRL1, a CDRL2, and a CDRL3, wherein the CDRH1, CDRH2, and CDRH3 comprise or consist of the amino acid sequences set forth in SEQ ID NOs.: 106-108, respectively, and the CDRL1, CDRL2, and CDRL3 comprise or consist of the amino acid sequences set forth in SEQ ID NOs.: 169-171, respectively. In further embodiments, a composition is capable of neutralizing a SARS-CoV-2 infection, or a virus pseudotyped with SARS-CoV-2, with an IC50 of about 0.07 to about 0.08 μg/ml. In certain embodiments, a composition comprises a first antibody or antigen-binding fragment, comprising a VH comprising or consisting of the amino acid sequence as set forth in SEQ ID NO: 178 and a VL comprising or consisting of the amino acid sequence as set forth in SEQ ID NO.: 182 or SEQ ID NO.: 190; and a second antibody or antigen-binding fragment comprising, a VH comprising or consisting of the amino acid sequence as set forth in SEQ ID NO.: 105 and a VL comprising of consisting of the amino acid sequence as set forth in SEQ ID NO.: 168. In certain embodiments, a composition comprises a first antibody or antigen-binding fragment comprising a heavy chain variable domain (VH) comprising a CDRH1, a CDRH2, and a CDRH3, and a light chain variable domain (VL) comprising a CDRL1, a CDRL2, and a CDRL3, wherein the CDRH1, CDRH2, and CDRH3 comprise or consist of the amino acid sequences set forth in SEQ ID NOs.: 179-181, respectively, and the CDRL1, CDRL2, and CDRL3 comprise or consist of the amino acid sequences set forth in SEQ ID NOs.: 183-185, respectively, and a second antibody or antigen-binding fragment comprising a heavy chain variable domain (VH) comprising a CDRH1, a CDRH2, and a CDRH3, and a light chain variable domain (VL) comprising a CDRL1, a CDRL2, and a CDRL3, wherein the CDRH1, CDRH2, and CDRH3 comprise or consist of the amino acid sequences set forth in SEQ ID NOs.: 106-108, respectively, and the CDRL1, CDRL2, and CDRL3 comprise or consist of the amino acid sequences set forth in SEQ ID NOs.: 169-171, respectively.

In certain embodiments, a composition comprises a first vector comprising a first plasmid, and a second vector comprising a second plasmid, wherein the first plasmid comprises a polynucleotide encoding a heavy chain, VH, or VH+CH, and a second plasmid comprises a polynucleotide encoding the cognate light chain, VL, or VL+CL of the antibody or antigen-binding fragment thereof. In certain embodiments, a composition comprises a polynucleotide (e.g., mRNA) coupled to a suitable delivery vehicle or carrier. Exemplary vehicles or carriers for administration to a human subject include a lipid or lipid-derived delivery vehicle, such as a liposome, solid lipid nanoparticle, oily suspension, submicron lipid emulsion, lipid microbubble, inverse lipid micelle, cochlear liposome, lipid microtubule, lipid microcylinder, or lipid nanoparticle (LNP) or a nanoscale platform (see, e.g., Li et al. Wilery Interdiscip Rev. Nanomed Nanobiotechnol. 11(2):e1530 (2019)). Principles, reagents, and techniques for designing appropriate mRNA and and formulating mRNA-LNP and delivering the same are described in, for example, Pardi et al. (J Control Release 2/7345-351 (2015)); Thess et al. (Mol Ther 23: 1456-1464 (2015)); Thran et al. (EMBO Mol Med 9(10):1434-1448 (2017); Kose et al. (Sci. Immunol. 4 eaaw6647 (2019); and Sabnis et al. (Mol. Ther. 26:1509-1519 (2018)), which techniques, include capping, codon optimization, nucleoside modification, purification of mRNA, incorporation of the mRNA into stable lipid nanoparticles (e.g., ionizable cationic lipid/phosphatidylcholine/cholesterol/PEG-lipid; ionizable lipid:distearoyl PC:cholesterol:polyethylene glycol lipid), and subcutaneous, intramuscular, intradermal, intravenous, intraperitoneal, and intratracheal administration of the same, are incorporated herein by reference.

Methods and Uses

Also provided herein are methods for use of an antibody or antigen-binding fragment, nucleic acid, vector, cell, or composition of the present disclosure in the diagnosis of SARS-CoV-2 (e.g., in a human subject, or in a sample obtained from a human subject).

Methods of diagnosis (e.g., in vitro, ex vivo) may include contacting an antibody, antibody fragment (e.g., antigen binding fragment) with a sample. Such samples may be isolated from a subject, for example an isolated tissue sample taken from, for example, nasal passages, sinus cavities, salivary glands, lung, liver, pancreas, kidney, ear, eye, placenta, alimentary tract, heart, ovaries, pituitary, adrenals, thyroid, brain, skin or blood. The methods of diagnosis may also include the detection of an antigen/antibody complex, in particular following the contacting of an antibody or antibody fragment with a sample. Such a detection step can be performed at the bench, i.e. without any contact to the human or animal body. Examples of detection methods are well-known to the person skilled in the art and include, e.g., ELISA (enzyme-linked immunosorbent assay), including direct, indirect, and sandwich ELISA.

Also provided herein are methods of treating a subject using an antibody or antigen-binding fragment of the present disclosure, or a composition comprising the same, wherein the subject has, is believed to have, or is at risk for having an infection by SARS-CoV-2. “Treat,” “treatment,” or “ameliorate” refers to medical management of a disease, disorder, or condition of a subject (e.g., a human or non-human mammal, such as a primate, horse, cat, dog, goat, mouse, or rat). In general, an appropriate dose or treatment regimen comprising an antibody or composition of the present disclosure is administered in an amount sufficient to elicit a therapeutic or prophylactic benefit. Therapeutic or prophylactic/preventive benefit includes improved clinical outcome; lessening or alleviation of symptoms associated with a disease; decreased occurrence of symptoms; improved quality of life; longer disease-free status; diminishment of extent of disease, stabilization of disease state; delay or prevention of disease progression; remission; survival; prolonged survival; or any combination thereof. In certain embodiments, therapeutic or prophylactic/preventive benefit includes reduction or prevention of hospitalization for treatment of a SARS-CoV-2 infection (i.e., in a statistically significant manner). In certain embodiments, therapeutic or prophylactic/preventive benefit includes a reduced duration of hospitalization for treatment of a SARS-CoV-2 infection (i.e., in a statistically significant manner). In certain embodiments, therapeutic or prophylactic/preventive benefit includes a reduced or abrogated need for respiratory intervention, such as intubation and/or the use of a respirator device. In certain embodiments, therapeutic or prophylactic/preventive benefit includes reversing a late-stage disease pathology and/or reducing mortality.

A “therapeutically effective amount” or “effective amount” of an antibody, antigen-binding fragment, polynucleotide, vector, host cell, or composition of this disclosure refers to an amount of the composition or molecule sufficient to result in a therapeutic effect, including improved clinical outcome; lessening or alleviation of symptoms associated with a disease; decreased occurrence of symptoms; improved quality of life; longer disease-free status; diminishment of extent of disease, stabilization of disease state; delay of disease progression; remission; survival; or prolonged survival in a statistically significant manner. When referring to an individual active ingredient, administered alone, a therapeutically effective amount refers to the effects of that ingredient or cell expressing that ingredient alone. When referring to a combination, a therapeutically effective amount refers to the combined amounts of active ingredients or combined adjunctive active ingredient with a cell expressing an active ingredient that results in a therapeutic effect, whether administered serially, sequentially, or simultaneously. A combination may comprise, for example, two different antibodies that specifically bind a SARS-CoV-2 antigen, which in certain embodiments, may be the same or different Wuhan coronavirus antigen, and/or can comprise the same or different epitopes.

Accordingly, in certain embodiments, methods are provided for treating a SARS-CoV-2 infection in a subject, wherein the methods comprise administering to the subject an effective amount of an antibody, antigen-binding fragment, polynucleotide, vector, host cell, or composition as disclosed herein.

Subjects that can be treated by the present disclosure are, in general, human and other primate subjects, such as monkeys and apes for veterinary medicine purposes. Other model organisms, such as mice and rats, may also be treated according to the present disclosure. In any of the aforementioned embodiments, the subject may be a human subject. The subjects can be male or female and can be any suitable age, including infant, juvenile, adolescent, adult, and geriatric subjects.

A number of criteria are believed to contribute to high risk for severe symptoms or death associated with a SARS CoV-2 infection. These include, but are not limited to, age, occupation, general health, pre-existing health conditions, and lifestyle habits. In some embodiments, a subject treated according to the present disclosure comprises one or more risk factors.

In certain embodiments, a human subject treated according to the present disclosure is an infant, a child, a young adult, an adult of middle age, or an elderly person. In certain embodiments, a human subject treated according to the present disclosure is less than 1 year old, or is 1 to 5 years old, or is between 5 and 125 years old (e.g., 5, 10, 15, 20, 25, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75, 80, 85, 90, 95, 100, 105, 110, 115, or 125 years old, including any and all ages therein or therebetween). In certain embodiments, a human subject treated according to the present disclosure is 0-19 years old, 20-44 years old, 45-54 years old, 55-64 years old, 65-74 years old, 75-84 years old, or 85 years old, or older. Persons of middle, and especially of elderly age are believed to be at particular risk. In particular embodiments, the human subject is 45-54 years old, 55-64 years old, 65-74 years old, 75-84 years old, or 85 years old, or older. In some embodiments, the human subject is male. In some embodiments, the human subject is female.

In certain embodiments, a human subject treated according to the present disclosure is a resident of a nursing home or a long-term care facility, is a hospice care worker, is a healthcare provider or healthcare worker, is a first responder, is a family member or other close contact of a subject diagnosed with or suspected of having a SARS-CoV-2 infection, is overweight or clinically obese, is or has been a smoker, has or had chronic obstructive pulmonary disease (COPD), is asthmatic (e.g., having moderate to severe asthma), has an autoimmune disease or condition (e.g., diabetes), and/or has a compromised or depleted immune system (e.g., due to AIDS/HIV infection, a cancer such as a blood cancer, a lymphodepleting therapy such as a chemotherapy, a bone marrow or organ transplantation, or a genetic immune condition), has chronic liver disease, has cardiovascular disease, has a pulmonary or heart defect, works or otherwise spends time in close proximity with others, such as in a factory, shipping center, hospital setting, or the like.

In certain embodiments, a subject treated according to the present disclosure has received a vaccine for SARS-CoV-2 and the vaccine is determined to be ineffective, e.g., by post-vaccine infection or symptoms in the subject, by clinical diagnosis or scientific or regulatory criteria.

In certain embodiments, treatment is administered as peri-exposure prophylaxis. In certain embodiments, treatment is administered to a subject with mild-to-moderate disease, which may be in an outpatient setting. In certain embodiments, treatment is administered to a subject with moderate-to-severe disease, such as requiring hospitalization.

Typical routes of administering the presently disclosed compositions thus include, without limitation, oral, topical, transdermal, inhalation, parenteral, sublingual, buccal, rectal, vaginal, and intranasal. The term “parenteral”, as used herein, includes subcutaneous injections, intravenous, intramuscular, intrasternal injection or infusion techniques. In certain embodiments, administering comprises administering by a route that is selected from oral, intravenous, parenteral, intragastric, intrapleural, intrapulmonary, intrarectal, intradermal, intraperitoneal, intratumoral, subcutaneous, topical, transdermal, intracisternal, intrathecal, intranasal, and intramuscular. In particular embodiments, a method comprises orally administering the antibody, antigen-binding fragment, polynucleotide, vector, host cell, or composition to the subject.

Pharmaceutical compositions according to certain embodiments of the present invention are formulated so as to allow the active ingredients contained therein to be bioavailable upon administration of the composition to a patient. Compositions that will be administered to a subject or patient may take the form of one or more dosage units, where for example, a tablet may be a single dosage unit, and a container of a herein described an antibody or antigen-binding in aerosol form may hold a plurality of dosage units. Actual methods of preparing such dosage forms are known, or will be apparent, to those skilled in this art; for example, see Remington: The Science and Practice of Pharmacy, 20th Edition (Philadelphia College of Pharmacy and Science, 2000). The composition to be administered will, in any event, contain an effective amount of an antibody or antigen-binding fragment, polynucleotide, vector, host cell, or composition of the present disclosure, for treatment of a disease or condition of interest in accordance with teachings herein.

A composition may be in the form of a solid or liquid. In some embodiments, the carrier(s) are particulate, so that the compositions are, for example, in tablet or powder form. The carrier(s) may be liquid, with the compositions being, for example, an oral oil, injectable liquid or an aerosol, which is useful in, for example, inhalatory administration. When intended for oral administration, the pharmaceutical composition is preferably in either solid or liquid form, where semi solid, semi liquid, suspension and gel forms are included within the forms considered herein as either solid or liquid.

As a solid composition for oral administration, the pharmaceutical composition may be formulated into a powder, granule, compressed tablet, pill, capsule, chewing gum, wafer or the like. Such a solid composition will typically contain one or more inert diluents or edible carriers. In addition, one or more of the following may be present: binders such as carboxymethylcellulose, ethyl cellulose, microcrystalline cellulose, gum tragacanth or gelatin; excipients such as starch, lactose or dextrins, disintegrating agents such as alginic acid, sodium alginate, Primogel, corn starch and the like; lubricants such as magnesium stearate or Sterotex; glidants such as colloidal silicon dioxide; sweetening agents such as sucrose or saccharin; a flavoring agent such as peppermint, methyl salicylate or orange flavoring; and a coloring agent. When the composition is in the form of a capsule, for example, a gelatin capsule, it may contain, in addition to materials of the above type, a liquid carrier such as polyethylene glycol or oil.

The composition may be in the form of a liquid, for example, an elixir, syrup, solution, emulsion or suspension. The liquid may be for oral administration or for delivery by injection, as two examples. When intended for oral administration, preferred compositions contain, in addition to the present compounds, one or more of a sweetening agent, preservatives, dye/colorant and flavor enhancer. In a composition intended to be administered by injection, one or more of a surfactant, preservative, wetting agent, dispersing agent, suspending agent, buffer, stabilizer and isotonic agent may be included.

Liquid pharmaceutical compositions, whether they be solutions, suspensions or other like form, may include one or more of the following adjuvants: sterile diluents such as water for injection, saline solution, preferably physiological saline, Ringer's solution, isotonic sodium chloride, fixed oils such as synthetic mono or diglycerides which may serve as the solvent or suspending medium, polyethylene glycols, glycerin, propylene glycol or other solvents; antibacterial agents such as benzyl alcohol or methyl paraben; antioxidants such as ascorbic acid or sodium bisulfite; chelating agents such as ethylenediaminetetraacetic acid; buffers such as acetates, citrates or phosphates and agents for the adjustment of tonicity such as sodium chloride or dextrose. The parenteral preparation can be enclosed in ampoules, disposable syringes or multiple dose vials made of glass or plastic. Physiological saline is a preferred adjuvant. An injectable pharmaceutical composition is preferably sterile.

A liquid composition intended for either parenteral or oral administration should contain an amount of an antibody or antigen-binding fragment as herein disclosed such that a suitable dosage will be obtained. Typically, this amount is at least 0.01% of the antibody or antigen-binding fragment in the composition. When intended for oral administration, this amount may be varied to be between 0.1 and about 70% of the weight of the composition. Certain oral pharmaceutical compositions contain between about 4% and about 75% of the antibody or antigen-binding fragment. In certain embodiments, pharmaceutical compositions and preparations according to the present invention are prepared so that a parenteral dosage unit contains between 0.01 to 10% by weight of antibody or antigen-binding fragment prior to dilution.

The composition may be intended for topical administration, in which case the carrier may suitably comprise a solution, emulsion, ointment or gel base. The base, for example, may comprise one or more of the following: petrolatum, lanolin, polyethylene glycols, bee wax, mineral oil, diluents such as water and alcohol, and emulsifiers and stabilizers. Thickening agents may be present in a composition for topical administration. If intended for transdermal administration, the composition may include a transdermal patch or iontophoresis device. The pharmaceutical composition may be intended for rectal administration, in the form, for example, of a suppository, which will melt in the rectum and release the drug. The composition for rectal administration may contain an oleaginous base as a suitable nonirritating excipient. Such bases include, without limitation, lanolin, cocoa butter and polyethylene glycol.

A composition may include various materials which modify the physical form of a solid or liquid dosage unit. For example, the composition may include materials that form a coating shell around the active ingredients. The materials that form the coating shell are typically inert, and may be selected from, for example, sugar, shellac, and other enteric coating agents. Alternatively, the active ingredients may be encased in a gelatin capsule. The composition in solid or liquid form may include an agent that binds to the antibody or antigen-binding fragment of the disclosure and thereby assists in the delivery of the compound. Suitable agents that may act in this capacity include monoclonal or polyclonal antibodies, one or more proteins or a liposome. The composition may consist essentially of dosage units that can be administered as an aerosol. The term aerosol is used to denote a variety of systems ranging from those of colloidal nature to systems consisting of pressurized packages. Delivery may be by a liquefied or compressed gas or by a suitable pump system that dispenses the active ingredients. Aerosols may be delivered in single phase, bi phasic, or tri phasic systems in order to deliver the active ingredient(s). Delivery of the aerosol includes the necessary container, activators, valves, subcontainers, and the like, which together may form a kit. One of ordinary skill in the art, without undue experimentation, may determine preferred aerosols.

It will be understood that compositions of the present disclosure also encompass carrier molecules for polynucleotides, as described herein (e.g., lipid nanoparticles, nanoscale delivery platforms, and the like).

The pharmaceutical compositions may be prepared by methodology well known in the pharmaceutical art. For example, a composition intended to be administered by injection can be prepared by combining a composition that comprises an antibody, antigen-binding fragment thereof, or antibody conjugate as described herein and optionally, one or more of salts, buffers and/or stabilizers, with sterile, distilled water so as to form a solution. A surfactant may be added to facilitate the formation of a homogeneous solution or suspension. Surfactants are compounds that non-covalently interact with the peptide composition so as to facilitate dissolution or homogeneous suspension of the antibody or antigen-binding fragment thereof in the aqueous delivery system.

In general, an appropriate dose and treatment regimen provide the composition(s) in an amount sufficient to provide therapeutic and/or prophylactic benefit (such as described herein, including an improved clinical outcome (e.g., a decrease in frequency, duration, or severity of diarrhea or associated dehydration, or inflammation, or longer disease-free and/or overall survival, or a lessening of symptom severity). For prophylactic use, a dose should be sufficient to prevent, delay the onset of, or diminish the severity of a disease associated with disease or disorder. Prophylactic benefit of the compositions administered according to the methods described herein can be determined by performing pre-clinical (including in vitro and in vivo animal studies) and clinical studies and analyzing data obtained therefrom by appropriate statistical, biological, and clinical methods and techniques, all of which can readily be practiced by a person skilled in the art.

Compositions are administered in an effective amount (e.g., to treat a SARS-CoV-2 infection), which will vary depending upon a variety of factors including the activity of the specific compound employed; the metabolic stability and length of action of the compound; the age, body weight, general health, sex, and diet of the subject; the mode and time of administration; the rate of excretion; the drug combination; the severity of the particular disorder or condition; and the subject undergoing therapy. In certain embodiments, following administration of therapies according to the formulations and methods of this disclosure, test subjects will exhibit about a 10% up to about a 99% reduction in one or more symptoms associated with the disease or disorder being treated as compared to placebo-treated or other suitable control subjects.

Generally, a therapeutically effective daily dose of an antibody or antigen binding fragment is (for a 70 kg mammal) from about 0.001 mg/kg (i.e., 0.07 mg) to about 100 mg/kg (i.e., 7.0 g); preferably a therapeutically effective dose is (for a 70 kg mammal) from about 0.01 mg/kg (i.e., 0.7 mg) to about 50 mg/kg (i.e., 3.5 g); more preferably a therapeutically effective dose is (for a 70 kg mammal) from about 1 mg/kg (i.e., 70 mg) to about 25 mg/kg (i.e., 1.75 g). For polynucleotides, vectors, host cells, and related compositions of the present disclosure, a therapeutically effective dose may be different than for an antibody or antigen-binding fragment.

In certain embodiments, a method comprises administering the antibody, antigen-binding fragment, polynucleotide, vector, host cell, or composition to the subject at 2, 3, 4, 5, 6, 7, 8, 9, 10 times, or more.

In certain embodiments, a method comprises administering the antibody, antigen-binding fragment, or composition to the subject a plurality of times, wherein a second or successive administration is performed at about 6, about 7, about 8, about 9, about 10, about 11, about 12, about 24, about 48, about 74, about 96 hours, or more, following a first or prior administration, respectively.

In certain embodiments, a method comprises administering the antibody, antigen-binding fragment, polynucleotide, vector, host cell, or composition at least one time prior to the subject being infected by SARS-CoV-2.

Compositions comprising an antibody, antigen-binding fragment, polynucleotide, vector, host cell, or composition of the present disclosure may also be administered simultaneously with, prior to, or after administration of one or more other therapeutic agents. Such combination therapy may include administration of a single pharmaceutical dosage formulation which contains a compound of the invention and one or more additional active agents, as well as administration of compositions comprising an antibody or antigen-binding fragment of the disclosure and each active agent in its own separate dosage formulation. For example, an antibody or antigen-binding fragment thereof as described herein and the other active agent can be administered to the patient together in a single oral dosage composition such as a tablet or capsule, or each agent administered in separate oral dosage formulations. Similarly, an antibody or antigen-binding fragment as described herein and the other active agent can be administered to the subject together in a single parenteral dosage composition such as in a saline solution or other physiologically acceptable solution, or each agent administered in separate parenteral dosage formulations. Where separate dosage formulations are used, the compositions comprising an antibody or antigen-binding fragment and one or more additional active agents can be administered at essentially the same time, i.e., concurrently, or at separately staggered times, i.e., sequentially and in any order; combination therapy is understood to include all these regimens.

In certain embodiments, a combination therapy is provided that comprises one or more anti-SARS-CoV-2 antibody (or one or more nucleic acid, host cell, vector, or composition) of the present disclosure and one or more anti-inflammatory agent and/or one or more anti-viral agent. In particular embodiments, the one or more anti-inflammatory agent comprises a corticosteroid such as, for example, dexamethasone, prednisone, or the like. In some embodiments, the one or more anti-inflammatory agents comprise a cytokine antagonist such as, for example, an antibody that binds to IL6 (such as siltuximab), or to IL-6R (such as tocilizumab), or to IL-1(3, IL-7, IL-8, IL-9, IL-10, FGF, G-CSF, GM-CSF, IFN-γ, IP-10, MCP-1, MIP-1A, MIP1-B, PDGR, TNF-α, or VEGF. In some embodiments, anti-inflammatory agents such as ruxolitinib and/or anakinra are used. In some embodiments, the one or more anti-viral agents comprise nucleotide analogs or nucelotide analog prodrugs such as, for example, remdesivir, sofosbuvir, acyclovir, and zidovudine. In particular embodiments, an anti-viral agent comprises lopinavir, ritonavir, favipiravir, or any combination thereof. In some embodiments, a combination therapy comprises leronlimab. Anti-inflammatory agents for use in a combination therapy of the present disclosure also include non-steroidal anti-inflammatory drugs (NSAIDS). It will be appreciated that in such a combination therapy, the one or more antibody (or one or more nucleic acid, host cell, vector, or composition) and the one or more anti-inflammatory agent and/or one or the more antiviral agent can be administered in any order and any sequence, or together.

In some embodiments, an antibody (or one or more nucleic acid, host cell, vector, or composition) is administered to a subject who has previously received one or more anti-inflammatory agent and/or one or more antiviral agent. In some embodiments, one or more anti-inflammatory agent and/or one or more antiviral agent is administered to a subject who has previously received an antibody (or one or more nucleic acid, host cell, vector, or composition).

In certain embodiments, a combination therapy is provided that comprises two or more anti-SARS-CoV-2 antibodies of the present disclosure. A method can comprise administering a first antibody to a subject who has received a second antibody, or can comprise administering two or more antibodies together. For example, in particular embodiments, a method is provided that comprises administering to the subject (a) a first antibody or antigen-binding fragment, when the subject has received a second antibody or antigen-binding fragment; (b) the second antibody or antigen-binding fragment, when the subject has received the first antibody or antigen-binding fragment; or (c) the first antibody or antigen-binding fragment, and the second antibody or antigen-binding fragment.

In a related aspect, uses of the presently disclosed antibodies, antigen-binding fragments, vectors, host cells, and compositions are provided.

In certain embodiments, an antibody, antigen-binding fragment, polynucleotide, vector, host cell, or composition is provided for use in a method of treating a SARS-CoV-2 infection in a subject.

In certain embodiments, an antibody, antigen-binding fragment, or composition is provided for use in a method of manufacturing or preparing a medicament for treating a SARS-CoV-2 infection in a subject.

The present disclosure also provides the following Embodiments.

Embodiment 1. An antibody, or an antigen-binding fragment thereof, comprising a heavy chain variable domain (VH) comprising a CDRH1, a CDRH2, and a CDRH3, and a light chain variable domain (VL) comprising a CDRL1, a CDRL2, and a CDRL3, wherein:

(i) the CDRH1 comprises or consists of the amino acid sequence set forth in any one of SEQ ID NOs.:106, 2, 56, 64, 80, 88, 96, 156, 179, 195, or 240, or a sequence variant thereof comprising one, two, or three acid substitutions, one or more of which substitutions is optionally a conservative substitution and/or is a substitution to a germline-encoded amino acid;

(ii) the CDRH2 comprises or consists of the amino acid sequence set forth in any one of SEQ ID NOs.:121, 3, 16-22, 57, 65, 81, 89, 97, 107, 122-126, 157, 180, 197, 199, or 241, or a sequence variant thereof comprising one, two, or three amino acid substitutions, one or more of which substitutions is optionally a conservative substitution and/or is a substitution to a germline-encoded amino acid;

(iii) the CDRH3 comprises or consists of the amino acid sequence set forth in any one of SEQ ID NOs.:108, 4, 25, 26, 58, 66, 82, 90, 98, 104, 127, 128, 158, 181, 201, 203, or 242, or a sequence variant thereof comprising one, two, or three amino acid substitutions, one or more of which substitutions is optionally a conservative substitution and/or is a substitution to a germline-encoded amino acid;

(iv) the CDRL1 comprises or consists of the amino acid sequence set forth in any one of SEQ ID NOs.:169, 6, 51-54, 60, 68, 73, 74, 84, 92, 100, 110, 160, 183, 235, or 244, or a sequence variant thereof comprising one, two, or three amino acid substitutions, one or more of which substitutions is optionally a conservative substitution and/or is a substitution to a germline-encoded amino acid;

(v) the CDRL2 comprises or consists of the amino acid sequence set forth in any one of SEQ ID NOs.:170, 7, 61, 69, 85, 93, 101, 111, 161, 184, 236 or 245, or a sequence variant thereof comprising one, two, or three amino acid substitutions, one or more of which substitutions is optionally a conservative substitution and/or is a substitution to a germline-encoded amino acid; and/or

(vi) the CDRL3 comprises or consists of the amino acid sequence set forth in any one of SEQ ID NOs.:171, 8, 62, 70, 77, 78, 86, 94, 102, 112, 151-154, 162, 185, 237, or 246, or a sequence variant thereof comprising having one, two, or three amino acid substitutions, one or more of which substitutions is optionally a conservative substitution and/or is a substitution to a germline-encoded amino acid,

wherein the antibody or antigen-binding fragment is capable of binding to a SARS-CoV-2 surface glycoprotein (S) expressed on a cell surface of a host cell, on a SARS-CoV-2 virion, or both.

Embodiment 2. The antibody or antigen-binding fragment of Embodiment 1, which is capable of neutralizing a SARS-CoV-2 infection in an in vitro model of infection and/or in an in vivo animal model of infection and/or in a human.

Embodiment 3. The antibody or antigen-binding fragment of any one of Embodiments 1-2, comprising the CDRH1, CDRH2, CDRH3, CDRL1, CDRL2, and CDRL3 amino acid sequences set forth in SEQ ID NOs.:

(i) 106, 121, 108, 169, 170, and 171, respectively;

(ii) 2-4 and 6-8 or 235-237, respectively;

(iii) 2, any one of 16-22, 4, and 6-8 or 235-237, respectively;

(iv) 2, 3, any one of 25-26, and 6-8 or 235-237, respectively;

(v) 2-4, 51, 7 or 236, and 8 or 237, respectively;

(vi) 2-4, 52, 7 or 236, and 8 or 237, respectively;

(vii) 2-4, 53, 7 or 236, and 8 or 237, respectively;

(viii) 2-5, 54, 7 or 236, and 8 or 237, respectively;

(ix) 56-58 and 60-62, respectively;

(x) 64-66 and 68-70, respectively;

(xi) 64-66, 73 or 74, 69, and 70, respectively;

(xii) 64-66, 68, 69, and 77 or 78, respectively;

(xiii) 80-82 and 84-86, respectively;

(xiv) 88-90 and 92-94, respectively;

(xv) 96-98 and 101-102, respectively;

(xvi) 96, 97, 104, and 100-102, respectively;

(xvii) 106-108 and 169-171, respectively;

(xviii) 106, any one of 121-126, 108, and 169-171, respectively;

(xix) 106, 107, 127 or 128, and 169-171, respectively;

(xx) 106, 107 or any one of 121-126, 108 and 169-171, respectively;

(xxi) 156-158 and 160-162, respectively;

(xxii) 106, 123, 127, and 169-171, respectively;

(xxiii) 2, 17, 25, 6 or 235 or any one of 51-54, 7 or 236, and 8 or 237, respectively;

(xxiv) 2, 20, 25, 6 or 235 or any one of 51-54, 7 or 236, and 8 or 237, respectively;

(xxv) 179-181 and 183-185, respectively

(xxvi) 195, 180, 181 and 183-185, respectively;

(xxvii) 195, 197, 181 and 183-185, respectively;

(xxviii) 195, 199, 181 and 183-185, respectively;

(xxiv) 195, 197, 201 and 183-185, respectively;

(xxx) 195, 197, 203 and 183-185, respectively;

(xxxi) 195, 199, 201 and 183-185, respectively;

(xxxii) 195, 199, 203 and 183-185, respectively;

(xxxiii) 179, 180, 181 and 183-185, respectively;

(xxxiv) 179, 197, 181 and 183-185, respectively;

(xxxv) 179, 199, 181 and 183-185, respectively;

(xxxvi) 179, 197, 201 and 183-185, respectively;

(xxxvii) 179, 197, 203 and 183-185, respectively;

(xxxviii) 179, 199, 201 and 183-185, respectively;

(xxxix) 179, 199, 203 and 183-185, respectively;

(xxxx) 179, 180, 201 and 183-185, respectively;

(xxxxi) 179, 180, 203 and 183-185, respectively; or

(xxxxii) 240-242 and 244-246, respectively.

Embodiment 4. The antibody or antigen-binding fragment of any one of Embodiments 1-3, comprising:

(i) the CDRH1 amino acid sequence set forth in SEQ ID NO.:106;

(ii) the CDRH2 amino acid sequence set forth in SEQ ID NO.:121, SEQ ID NO.:107, SEQ ID NO.:122, SEQ ID NO.:123, SEQ ID NO.:124, SEQ ID NO.:125, or SEQ ID NO.:126;

(iii) the CDRH3 amino acid sequence set forth in SEQ ID NO.:108, SEQ ID NO.:127, or SEQ ID NO.:128;

(iv) the CDRL1 amino acid sequence set forth in SEQ ID NO.:169;

(v) the CDRL2 amino acid sequence set forth in SEQ ID NO.:170; and

(vi) the CDRL3 amino acid sequence set forth in SEQ ID NO.:171,

wherein, optionally, the antibody or antigen-binding fragment comprises the CDRH1, CDRH2, CDRH3, CDRL1, CDRL2, and CDRL3 amino acid sequences set forth in:

(a) SEQ ID NOs.:106, 121, 108, 169, 170, and 171, respectively;

(b) SEQ ID NOs.: 106, 121, 127, 169, 170, and 171, respectively;

(c) SEQ ID NOs.: 106, 121, 128, 169, 170, and 171, respectively;

(d) SEQ ID NOs.: 106, 107, 108, 169, 170, and 171, respectively;

(e) SEQ ID NOs.: 106, 107, 127, 169, 170, and 171, respectively;

(f) SEQ ID NOs.: 106, 107, 128, 169, 170, and 171, respectively;

(g) SEQ ID NOs.: 106, 122, 108, 169, 170, and 171, respectively;

(h) SEQ ID NOs.: 106, 122, 127, 169, 170, and 171, respectively;

(i) SEQ ID NOs.: 106, 122, 128, 169, 170, and 171, respectively;

(j) SEQ ID NOs.: 106, 123, 108, 169, 170, and 171, respectively;

(k) SEQ ID NOs.: 106, 123, 127, 169, 170, and 171, respectively;

(l) SEQ ID NOs.: 106, 123, 128, 169, 170, and 171, respectively;

(m) SEQ ID NOs.: 106, 124, 108, 169, 170, and 171, respectively;

(n) SEQ ID NOs.: 106, 124, 127, 169, 170, and 171, respectively;

(o) SEQ ID NOs.: 106, 124, 128, 169, 170, and 171, respectively;

(p) SEQ ID NOs.: 106, 125, 108, 169, 170, and 171, respectively;

(q) SEQ ID NOs.: 106, 125, 127, 169, 170, and 171, respectively;

(r) SEQ ID NOs.: 106, 125, 128, 169, 170, and 171, respectively;

(s) SEQ ID NOs.: 106, 126, 108, 169, 170, and 171, respectively;

(t) SEQ ID NOs.: 106, 126, 127, 169, 170, and 171, respectively; or

(u) SEQ ID NOs.: 106, 126, 128, 169, 170, and 171, respectively.

Embodiment 5. An antibody or an antigen-binding fragment thereof, comprising a heavy chain variable domain (VH) comprising the CDRH1 amino acid sequence set forth in SEQ ID NO.:106, the CDRH2 amino acid sequence set forth in SEQ ID NO.:121, and the CDRH3 amino acid sequence set forth in SEQ ID NO.:108, and a light chain variable domain (VL) comprising a CDRL1 amino acid sequence set forth in SEQ ID NO.:169, a CDRL2 amino acid sequence set forth in SEQ ID NO.:170, and the CDRL3 amino acid sequence set forth in SEQ ID NO.:171,

wherein the antibody or antigen binding fragment is capable of binding to a SARS-CoV-2 surface glycoprotein (S): expressed on a cell surface of a host cell; on a virion; or both.

Embodiment 6. The antibody or antigen-binding fragment of Embodiment 5, which is capable of neutralizing a SARS-CoV-2 infection in an in vitro model of infection and/or in an in vivo animal model of infection and/or in a human.

Embodiment 7. The antibody or antigen-binding fragment of any one of Embodiments 1-6, wherein:

(i) the VH comprises or consists of an amino acid sequence having at least 85% identity to the amino acid sequence set forth in any one of SEQ ID NOs.:113, 1, 9-15, 23, 24, 27, 28-46, 55, 63, 79, 87, 95, 103, 105, 114-120, 129-146, 155, 172, 176-178, 194, 196, 198, 200, 202, 239, and 267, wherein the variation as compared to the reference VH amino acid sequence, if present, is optionally limited to one or more framework regions and/or the variation comprises one or more substitution to a germline-encoded amino acid; and/or

(ii) the VL comprises or consists of an amino acid sequence having at least 85% identity to the amino acid sequence set forth in any one of SEQ ID NOs.:168, 5, 47-50, 59, 67, 71-72, 75, 76, 83, 91, 99, 109, 147-150, 159, 182, 190, 234, and 243, wherein the variation as compared to the reference VH amino acid sequence, if present, is optionally limited to one or more framework regions and/or the variation comprises one or more substitution to a germline-encoded amino acid.

Embodiment 8. The antibody or antigen-binding fragment of any one of Embodiments 1-7, wherein the VH comprises or consists of any VH amino acid sequence set forth in Table 2, and wherein the VL comprises or consists of any VL amino acid sequence set forth in Table 2, wherein, optionally, the VH and the VL comprise or consist of the amino acid sequences set forth in SEQ ID NOs.:

(i) 113 and 168, respectively;

(ii) 1 and 5 or 234, respectively;

(iii) any one of 9-15 and 5 or 234, respectively;

(iv) 23 or 24 and 5 or 234, respectively;

(v) 27 and 5 or 234, respectively;

(vi) any one of 28-46 and 5 or 234, respectively;

(vii) 1 and any one of 47-50, respectively;

(viii) any one of 9-15 and any one of 47-50, respectively;

(ix) 23 or 24 and any one of 47-50, respectively;

(x) 27 and any one of 47-50, respectively;

(xi) any one of 28-46 and any one of 47-50, respectively;

(xii) 55 and 59, respectively;

(xiii) 63 and 67, respectively;

(xiv) 63 and 71 or 72, respectively;

(xv) 63 and 75 or 76, respectively;

(xvi) 79 and 83, respectively;

(xvii) 87 and 91, respectively;

(xviii) 95 and 99, respectively;

(xix) 103 and 99, respectively;

(xx) 105 and 168, respectively;

(xxi) any one of 114-120 or 267 and 168, respectively;

(xxii) 129 and 168, respectively;

(xxiii) any one of 130-146 and 168, respectively;

(xxiv) 105 and any one of 147-150, respectively;

(xxv) any one of 113-120 and any one of 147-150, respectively;

(xxvi) any one of 130-146 and any one of 147-150, respectively;

(xxvii) 155 and 159, respectively;

(xxviii) 172 and 168, respectively;

(xxix) 176 or 177 and 5 or 234 or any one of 47-50, respectively;

(xxx) 178 and 182 or 190, respectively;

(xxxi) 194 and 182, respectively;

(xxxii) 196 and 182, respectively;

(xxxiii) 198 and 182, respectively;

(xxxiv) 200 and 182, respectively;

(xxxv) 202 and 182, respectively; or

(xxxvi) 239 and 243, respectively.

Embodiment 9. An antibody, or an antigen-binding fragment thereof, comprising a heavy chain variable domain (VH) and a light chain variable domain (VL), wherein the VH comprises or consists of the amino acid sequence set forth in SEQ ID NO.:113 and the VL comprises or consists of the amino acid sequence set forth in SEQ ID NO.:168.

Embodiment 10. An antibody, or an antigen-binding fragment thereof, comprising a heavy chain variable domain (VH) and a light chain variable domain (VL), wherein the VH comprises or consists of the amino acid sequence set forth in any one of SEQ ID NOs.:105, 114-120, 129-146, 172, and 267, and the VL comprises or consists of the amino acid sequence set forth in SEQ ID NO.:168.

Embodiment 11. An antibody, or antigen-binding fragment thereof, comprising a heavy chain variable domain (VH) and a light chain variable domain (VL), wherein the VH comprises or consists of the amino acid sequence set forth in SEQ ID NO.:79 and the VL comprises or consists of the amino acid sequence set forth in SEQ ID NO.:83.

Embodiment 12. An antibody, or antigen-binding fragment thereof, comprising a heavy chain variable domain (VH) comprising a CDRH1, a CDRH2, and a CDRH3, and a light chain variable domain (VL) comprising a CDRL1, a CDRL2, and a CDRL3, wherein the CDRH1, CDRH2, and CDRH3 comprise or consist of the amino acid sequences set forth in SEQ ID NOs.:80-82, respectively, and the CDRL1, CDRL2, and CDRL3 comprise or consist of the amino acid sequences set forth in SEQ ID NOs.:84-86, respectively,

wherein the antibody or antigen-binding fragment is capable of binding to a SARS-CoV-2 surface glycoprotein (S) expressed on a cell surface of a host cell, on a SARS-CoV-2 virion, or both.

Embodiment 13. An antibody, or antigen-binding fragment thereof, comprising a heavy chain variable domain (VH) and a light chain variable domain (VL), wherein the VH comprises or consists of the amino acid sequence set forth in SEQ ID NO.:105 and the VL comprises or consists of the amino acid sequence set forth in SEQ ID NO.:168.

Embodiment 14. An antibody, or antigen-binding fragment thereof, comprising a heavy chain variable domain (VH) comprising a CDRH1, a CDRH2, and a CDRH3, and a light chain variable domain (VL) comprising a CDRL1, a CDRL2, and a CDRL3, wherein the CDRH1, CDRH2, and CDRH3 comprise or consist of the amino acid sequences set forth in SEQ ID NOs.:106-108, respectively, and the CDRL1, CDRL2, and CDRL3 comprise or consist of the amino acid sequences set forth in SEQ ID NOs.: 169-171, respectively,

wherein the antibody or antigen-binding fragment is capable of binding to a SARS-CoV-2 surface glycoprotein (S) expressed on a cell surface of a host cell, on a SARS-CoV-2 virion, or both.

Embodiment 15. An antibody, or antigen-binding fragment thereof, comprising a heavy chain variable domain (VH) and a light chain variable domain (VL), wherein the VH comprises or consists of the amino acid sequence set forth in SEQ ID NO: 178 and the VL comprises or consists of the amino acid sequence set forth in SEQ ID NO.: 182 or SEQ ID NO.:190.

Embodiment 16. An antibody, or antigen-binding fragment thereof, comprising a heavy chain variable domain (VH) comprising a CDRH1, a CDRH2, and a CDRH3, and a light chain variable domain (VL) comprising a CDRL1, a CDRL2, and a CDRL3, wherein the CDRH1, CDRH2, and CDRH3 comprise or consist of the amino acid sequences set forth in SEQ ID NOs.:179-181, respectively, and the CDRL1, CDRL2, and CDRL3 comprise or consist of the amino acid sequences set forth in SEQ ID NOs.: 183-185, respectively,

wherein the antibody or antigen-binding fragment is capable of binding to a SARS-CoV-2 surface glycoprotein (S) expressed on a cell surface of a host cell, on a SARS-CoV-2 virion, or both.

Embodiment 17. The antibody or antigen-binding fragment of any one of Embodiments 1-16, which:

(i) recognizes an epitope in the ACE2 receptor binding motif (RBM, SEQ ID NO.:167) of a SARS-CoV-2;

(ii) is capable of blocking an interaction between SARS-CoV-2 (e.g., a SARS-CoV-2 RBM) and ACE2;

(ii) is capable of binding to SARS-CoV-2 S protein with greater avidity than to SARS coronavirus S protein;

(iii) recognizes an epitope that is conserved in the ACE2 RBM of SARS-CoV-2 and in an ACE2 RBM of SARS coronavirus;

(vi) is cross-reactive against SARS-CoV-2 and SARS coronavirus;

(vii) recognizes an epitope in the SARS-CoV-2 surface glycoprotein that is not in the ACE2 RBM;

or

(viii) any combination of (i)-(vii).

Embodiment 18. The antibody or antigen-binding fragment of any one of Embodiments 1-17, which is capable of inhibiting an interaction between SARS-CoV-2 and any one or more of DC-SIGN, L-SIGN, and SIGLEC-1.

Embodiment 19. The antibody or antigen-binding fragment of any one of Embodiments 1-18, which is capable of inhibiting an interaction between SARS-CoV-2 and any one or more of: DC-SIGN; L-SIGN; SIGLEC-1; CD22; CD33; CLEC4M, SIGLEC-16; SIGLEC-15; SIGLEC-14; SIGLEC-12; SIGLEC-11; SIGLEC-10; SIGLEC-9; SIGLEC-8; SIGLEC-7; SIGLEC-6; SIGLEC-5; or any combination thereof.

Embodiment 20. The antibody or antigen-binding fragment of any one of Embodiments 1-19, which is a IgG, IgA, IgM, IgE, or IgD isotype.

Embodiment 21. The antibody or antigen-binding fragment of any one of Embodiments 1-20, which is an IgG isotype selected from IgG1, IgG2, IgG3, and IgG4.

Embodiment 22. The antibody or antigen-binding fragment of any one of Embodiments 1-21, which is human, humanized, or chimeric.

Embodiment 23. The antibody or antigen-binding fragment of any one of Embodiments 1-22, wherein the antibody, or the antigen-binding fragment, comprises a human antibody, a monoclonal antibody, a purified antibody, a single chain antibody, a Fab, a Fab′, a F(ab′)2, a Fv, a scFv, or a scFab.

Embodiment 24. The antibody or antigen-binding fragment of Embodiment 23, wherein the scFab comprises:

(i) the amino acid sequence set forth in any one of SEQ ID NOs.:218-219 and 226-227;

(ii) a VL comprising the amino acid sequence set forth in SEQ ID NO.:168 and a VH comprising the amino acid sequence set forth in SEQ ID NO.: 105 or SEQ ID NO.:113; or

(iii) a CDRH1 comprising the amino acid sequence set forth in SEQ ID NO.: 106, a CDRH2 comprising the amino acid sequence set forth in SEQ ID NO.:107 or 121, a CDRH3 comprising the amino acid sequence set forth in SEQ ID NO.:108, a CDRL1 comprising the amino acid sequence set forth in SEQ ID NO.:169, a CDRL2 comprising the amino acid sequence set forth in SEQ ID NO.:170, and a CDRL3 comprising the amino acid sequence set forth in SEQ ID NO.:171.

Embodiment 25. The antibody or antigen-binding fragment of Embodiment 23, wherein the scFv comprises:

(i) the amino acid sequence set forth in any one of SEQ ID NOs.:220-221 or 228-229;

(ii) a VL comprising the amino acid sequence set forth in SEQ ID NO.:168 and a VH comprising the amino acid sequence set forth in SEQ ID NO.:105 or SEQ ID NO.:113; or

(iii) a CDRH1 comprising the amino acid sequence set forth in SEQ ID NO.:106, a CDRH2 comprising the amino acid sequence set forth in SEQ ID NO.:107 or 121, a CDRH3 comprising the amino acid sequence set forth in SEQ ID NO.:108, a CDRL1 comprising the amino acid sequence set forth in SEQ ID NO.:169, a CDRL2 comprising the amino acid sequence set forth in SEQ ID NO.:170, and a CDRL3 comprising the amino acid sequence set forth in SEQ ID NO.:171.

Embodiment 26. The antibody or antigen-binding fragment of Embodiment 25, wherein the scFv comprises more than one VH domain and more than one VL domain.

Embodiment 27. The antibody or antigen-binding fragment of Embodiment 26, wherein the scFv comprises:

(i) the amino acid sequence as set forth in any one of SEQ ID NOs.:222-225 or SEQ ID NOs.:230-233;

(ii) two VL domains, each comprising the amino acid sequence as set forth in SEQ ID NO.:168, and two VH domains, each comprising the amino acid sequence as set forth in SEQ ID NO.:105 or SEQ ID NO.:113; or

(iii) two VL domains, each comprising a CDRL1 comprising the amino acid sequence set forth in SEQ ID NO.:169, a CDRL2 comprising the amino acid sequence set forth in SEQ ID NO.:170, and a CDRL3 comprising the amino acid sequence set forth in SEQ ID NO.:171, and two VH domains, each comprising a CDRH1 comprising the amino acid sequence set forth in SEQ ID NO.:106, a CDRH2 comprising the amino acid sequence set forth in SEQ ID NO.:107 or 121, a CDRH3 comprising the amino acid sequence set forth in SEQ ID NO.:108.

Embodiment 28. The antibody or antigen-binding fragment of any one of Embodiments 1-27, wherein the antibody or antigen-binding fragment is a multi-specific antibody or antigen-binding fragment.

Embodiment 29. The antibody or antigen-binding fragment of Embodiment 28, wherein the antibody or antigen-binding fragment is a bispecific antibody or antigen-binding fragment.

Embodiment 30. The antibody or antigen-binding fragment of Embodiment 28 or 29, comprising:

(i) a first VH and a first VL; and

(ii) a second VH and a second VL,

wherein the first VH and the second VH are different and each independently comprise an amino acid sequence having at least 85% identity to the amino acid sequence set forth in any one of SEQ ID NOs.:113, 1, 9-15, 23, 24, 27-46, 55, 63, 79, 87, 95, 103, 105, 114-120, 129-146, 155, 172, 176-178, 194, 196, 198, 200, 202, 239, and 267,

wherein the first VL and the second VL are different and each independently comprise an amino acid sequence having at least 85% identity to the amino acid sequence set forth in any one of SEQ ID NOs.:168, 5, 47-50, 59, 67, 71, 72, 75, 76, 83, 91, 99, 109, 147-150, 159, 182, 190, 234, and 243;

and wherein the first VH and the first VL together form a first antigen-binding site, and wherein the second VH and the second VL together form a second antigen-binding site.

Embodiment 31. The antibody or antigen-binding fragment of any one of Embodiments 1-30, wherein the antibody or antigen-binding fragment further comprises a Fc polypeptide or a fragment thereof.

Embodiment 32. The antibody or antigen-binding fragment of Embodiment 31, wherein the Fc polypeptide or fragment thereof comprises:

(i) a mutation that enhances binding to a FcRn as compared to a reference Fc polypeptide that does not comprise the mutation; and/or

(ii) a mutation that enhances binding to a FcγR as compared to a reference Fc polypeptide that does not comprise the mutation.

Embodiment 33. The antibody or antigen-binding fragment of Embodiment 32, wherein the mutation that enhances binding to a FcRn comprises: M428L; N434S; N434H; N434A; N434S; M252Y; S254T; T256E; T250Q; P257I; Q311I; D376V; T307A; E380A; or any combination thereof.

Embodiment 34. The antibody or antigen-binding fragment of Embodiment 32 or 33, wherein the mutation that enhances binding to FcRn comprises:

-   -   (i) M428L/N434S;     -   (ii) M252Y/S254T/T256E;     -   (iii) T250Q/M428L;     -   (iv) P257I/Q311I;     -   (v) P257I/N434H;     -   (vi) D376V/N434H;     -   (vii) T307A/E380A/N434A; or     -   (viii) any combination of (i)-(vii).

Embodiment 35. The antibody or antigen-binding fragment of any one of Embodiments 32-34, wherein the mutation that enhances binding to FcRn comprises M428L/N434S.

Embodiment 36. The antibody or antigen-binding fragment of any one of Embodiments 32-35, wherein the mutation that enhances binding to a FcγR comprises S239D; I332E; A330L; G236A; or any combination thereof.

Embodiment 37. The antibody or antigen-binding fragment of any one of Embodiments 32-36, wherein the mutation that enhances binding to a FcγR comprises:

(i) S239D/I332E;

(ii) S239D/A330L/I332E;

(iii) G236A/S239D/I332E; or

(iv) G236A/A330L/I332E.

Embodiment 38. The antibody or antigen-binding fragment of any one of Embodiments 1-37:

which comprises a mutation that alters glycosylation, wherein the mutation that alters glycosylation comprises N297A, N297Q, or N297G; and/or

which is aglycosylated and/or afucosylated.

Embodiment 39. The antibody or antigen-binding fragment of any one of Embodiments 31-38, wherein the Fc polypeptide comprises a L234A mutation and a L235A mutation.

Embodiment 40. The antibody or antigen-binding fragment of any one of Embodiments 1-39, wherein the antibody or antigen-binding fragment binds to the SARS-CoV-2 S protein, as measured using biolayer interferometry.

Embodiment 41. The antibody or antigen-binding fragment of Embodiment 40, wherein the antibody or antigen-binding fragment binds to the SARS-CoV-2 S protein with a KD of less than about 4.5×10⁻⁹ M, such as less than 4.5×10⁻⁹ M.

Embodiment 42. The antibody or antigen-binding fragment of Embodiment 40 or 41, wherein the antibody or antigen-binding fragment binds to the SARS-CoV-2 S protein with a KD of less than about 1.0×10⁻¹⁰ M, such as less than 1.0×10⁻¹° M.

Embodiment 43. The antibody or antigen-binding fragment of any one of Embodiments 40-42, wherein the antibody or antigen-binding fragment binds to the SARS-CoV-2 S protein with a KD of less than about 1.0×10⁻¹¹M, such less than 1.0×10⁻¹¹ M.

Embodiment 44. The antibody or antigen-binding fragment of any one of Embodiments 40-43, wherein the antibody or antigen-binding fragment binds to the SARS-CoV-2 S protein with a KD of less than about 1×10⁻¹²M, such as less than 1×10⁻¹² M.

Embodiment 45. The antibody or antigen-binding fragment of any one of Embodiments 1-44, wherein the antibody or antigen-binding fragment is capable of neutralizing a SARS-CoV-2 infection and/or of neutralizing an infection of a target cell with an IC50 of about 16 to about 20 μg/ml.

Embodiment 46. The antibody or antigen-binding fragment of any one of Embodiments 1-45, wherein the antibody or antigen-binding fragment is capable of neutralizing a SARS-CoV-2 infection and/or of neutralizing an infection of a target cell with an IC50 of about 0.3 to about 0.4 μg/ml or about 3 to about 4 nM.

Embodiment 47. The antibody or antigen-binding fragment of any one of Embodiments 1-46, wherein the antibody or antigen-binding fragment is capable of inducing antibody-dependent cell-mediated cytotoxicity (ADCC) and/or antibody dependent cellular phagocytosis (ADCP) against a target cell infected by a SARS-CoV-2.

Embodiment 48. The antibody or antigen-binding fragment of any one of Embodiments 40-47, wherein a Fab of the antibody or antigen-binding fragment is capable of binding to SARS-CoV-2 S protein with a KD of 2.0×10⁻⁹ or less, 1.9×10⁻⁹ or less, or 1.8×10⁻⁹ or less.

Embodiment 49. The antibody or antigen-binding fragment of any one of Embodiments 1-48, wherein the antibody or antigen-binding fragment is capable of neutralizing infection by the SARS-CoV-2 and does not compete with a human ACE2 for binding to the SARS-CoV-2 S protein,

wherein, optionally, the neutralizing comprises neutralizing infection in an in vitro model of infection.

Embodiment 50. The antibody or antigen-binding fragment of any one of Embodiments 1-49, wherein the antibody or antigen-binding fragment is capable of neutralizing infection by the SARS-CoV-2 with an IC50 of 3.0 nM, 3.1 nM, 3.2 nM, 3.3 nM, 3.4 nM, 3.5 nM, 3.6 nM, 3.7 nM, 3.8 nM, 3.9 nM, or 4.0 nM.

Embodiment 51. The antibody or antigen-binding fragment of any one of Embodiments 47-50, wherein the inducing ADCC comprises activating a Natural Killer cell that comprises a V158 FcγRIIIa variant, a Natural Killer cell that comprises a F158 FcγRIIIa variant, or both.

Embodiment 52. The antibody or antigen-binding fragment of any one of Embodiments 47-51, wherein the ADCP comprises engaging a FcγRIIa and/or a FcγRIIIa expressed on the surface of a phagocytic cell, such as a monocyte, a macrophage, or a dendritic cell.

Embodiment 53. An antibody, or an antigen-binding fragment thereof, that competes for binding to a SARS-CoV-2 surface glycoprotein with the antibody or antigen-binding fragment of any one of Embodiments 1-52, wherein, optionally, the antibody or antigen-binding fragment is capable of inhibiting an interaction between SARS-CoV-2 and any one or more of DC-SIGN, L-SIGN, and SIGLEC-1.

Embodiment 54. An antibody, or an antigen-binding fragment thereof, that competes for binding to a SARS-CoV-2 surface glycoprotein with antibody S309 (VH SEQ ID NO.:105; VL SEQ ID NO.:168) and/or antibody S303 (VH SEQ ID NO.:63; VL SEQ ID NO.:67), wherein, optionally, the antibody or antigen-binding fragment is capable of inhibiting an interaction between SARS-CoV-2 and any one or more of DC-SIGN, L-SIGN, and SIGLEC-1.

Embodiment 55. An antibody, or an antigen-binding fragment thereof, that competes for binding to a SARS-CoV-2 surface glycoprotein with antibody S304 (VH SEQ ID NO.:79; VL SEQ ID NO.:81) and/or antibody S315 (VH SEQ ID NO.:178; VL SEQ ID NO.:182).

Embodiment 56. The antibody or antigen-binding fragment of any one of Embodiments 1-55, which is capable of binding to the SARS-CoV-2 surface glycoprotein when the SARS-CoV-2 surface glycoprotein is comprised in a prefusion trimer.

Embodiment 57. The antibody or antigen-binding fragment of any one of Embodiments 1-56, which is capable of binding to a Receptor Binding Domain (RBD) of the SARS-CoV-2 surface glycoprotein when the RBD is glycosylated and/or when the RBD is deglycosylated, wherein the binding is determined using surface plasmon resonance (SPR), wherein, optionally:

(1) the SPR is performed using a Biacore T200 instrument using a single-cycle kinetics approach, further optionally with a 3 minute injection period and a 20 minute dissociation period;

(2) the antibody or antigen-binding fragment is captured on a surface;

(3) the RBD is present at a concentration of were 0.8 nM, 3.1 nM, 12.5 nM, 50 nM, or 200 nM;

(4) the antibody or antigen-binding fragment binds to the glycosylated RBD with a KD of about 2.0 nM, about 1.9 nM, about 1.8 nM, about 1.7 nM, about 1.6 nM, about 1.5 nM, about 1.4 nM, about 1.3 nM, about 1.2 nM, about 1.1 nM, about 1.0 nM, about 0.9 nM, about 0.8 nM, about 0.7 nM, about 0.6 nM, about 0.5 nM, about 0.4 nM, or about 0.3 nM, or with a KD of 0.4 nM±0.05 nM, or with a KD of 0.45 nM±0.05 nM, or with a KD of 0.5 nM±0.05 nM, or with a KD of 0.6 nM±0.05 nM, or with a KD of 0.7 nM±0.05 nM, or with a KD of 1.7 nM±0.05 nM; and/or

(5) the antibody or antigen-binding fragment binds to the deglycosylated RBD with a KD of about 37.0 nM, about 8.0 nM, about 2.0 nM, about 1.9 nM, about 1.8 nM, about 1.7 nM, about 1.6 nM, about 1.5 nM, about 1.4 nM, about 1.3 nM, about 1.2 nM, about 1.1 nM, about 1.0 nM, or about 0.9 nM, or with a KD of 37.0 nM±0.05 nM, or with a KD of 8.0 nM±0.05 nM, or with a KD of 1.0 nM±0.05 nM, or with a KD of 0.9 nM±0.05 nM, or with a KD of 1.3 nM±0.05 nM, or with a KD of 1.8 nM 0.05 nM, or with a KD of 1.7 nM±0.05 nM.

Embodiment 58. The antibody or antigen-binding fragment of any one of Embodiments 1-57, which is capable of neutralizing an infection by the SARS-CoV-2 in a human lung cell, wherein, optionally, the human lung cell comprises a Calu-3 cell, wherein, further optionally, the antibody or antigen-binding fragment has a neutralization IC50 of about 97 ng/mL.

Embodiment 59. The antibody or antigen-binding fragment of any one of Embodiments 1-58, which is capable of binding to a human complement component C1q, wherein, optionally, binding to the C1q is determined using biolayer interferometry (BLI), such as using an Octet instrument.

Embodiment 60. The antibody or antigen-binding fragment of any one of Embodiments 1-59, which is capable of inhibiting SARS-CoV-2 surface glycoprotein-mediated cell-cell fusion.

Embodiment 61. The antibody or antigen-binding fragment of any one of Embodiments 1-60, which does not cause antibody-mediated enhancement of SARS-CoV-2 replication in a human donor-derived peripheral blood mononuclear cell (PBMC) or a dendritic cell.

Embodiment 62. The antibody or antigen-binding fragment of any one of Embodiments 1-61, comprising:

(i) a CH1-CH3 comprising or consisting of the amino acid sequence set forth in SEQ ID NO.:173 or 175; and/or

(ii) a CL comprising of consisting of the amino acid sequence set forth in SEQ ID NO.:174 or SEQ ID NO.:193.

Embodiment 63. An isolated antibody, or an antigen-binding fragment thereof, comprising a heavy chain variable domain (VH) that comprises the complementarity determining region (CDR)H1 amino acid sequence set forth in SEQ ID NO.:106, the CDRH2 amino acid sequence set forth in SEQ ID NO.:121, and the CDRH3 amino acid sequence set forth in SEQ ID NO.:108, and a light chain variable domain (VL) that comprises the CDRL1 amino acid sequence set forth in SEQ ID NO.:169, the CDRL2 amino acid sequence set forth in SEQ ID NO.:170, and the CDRL3 amino acid sequence set forth in SEQ ID NO.:171, wherein the antibody or antigen-binding fragment is capable of binding to a SARS-CoV-2 surface glycoprotein (S): expressed on a cell surface of a host cell; on a SARS-CoV-2 virion; or both.

Embodiment 64. The isolated antibody or antigen-binding fragment of any one of Embodiments 1-63, which is capable of binding to a surface glycoprotein (S) of:

(i) a SARS-CoV-2 Wuhan-Hu-1 (SEQ ID NO.:165);

(ii) a SARS-CoV-2 B.1.1.7;

(iii) a SARS-CoV-2 B.1.351;

(iv) a SARS-CoV-2 comprising any one or more of the following substitution mutations relative to SEQ ID NO.:165: N501Y; S477N; N439K; L452R; E484K; Y453F; A520S; K417N; K417V; S494P; N501T; 5477R; V367F; P384L; A522S; A522V; V382L; P330S; T478I; 5477I; P479S; or

(v) any combination of (i)-(iv).

Embodiment 65. The isolated antibody or antigen-binding fragment of Embodiment 63 or 64, which is capable of neutralizing a SARS-CoV-2 infection:

in an in vitro model of infection;

(ii) in an in vivo animal model of infection;

(iii) in a human; or

(iv) any combination of (i)-(iii).

Embodiment 66. The isolated antibody or antigen-binding fragment of Embodiment any one of Embodiments 63-65, wherein:

(i) the VH comprises or consists of an amino acid sequence having at least 85% identity to the amino acid sequence set forth in SEQ ID NO.:113; and/or

(ii) the VL comprises or consists of an amino acid sequence having at least 85% identity to the amino acid sequence set forth in SEQ ID NO.:168.

Embodiment 67. The isolated antibody or antigen-binding fragment of any one of Embodiments 63-66, wherein:

(i) the VH comprises or consists of an amino acid sequence having at least 90% identity to the amino acid sequence set forth in SEQ ID NO.:113; and/or

(ii) the VL comprises or consists of an amino acid sequence having at least 90% identity to the amino acid sequence set forth in SEQ ID NO.:168.

Embodiment 68. The isolated antibody or antigen-binding fragment of any one of Embodiments 63-67, wherein:

(i) the VH comprises or consists of an amino acid sequence having at least 95% identity to the amino acid sequence set forth in SEQ ID NO.:113; and/or

(ii) the VL comprises or consists of an amino acid sequence having at least 95% identity to the amino acid sequence set forth in SEQ ID NO.:168.

Embodiment 69. The isolated antibody or antigen-binding fragment any one of Embodiments 63-68, wherein:

(i) the VH comprises or consists of an amino acid sequence having at least 99% identity to the amino acid sequence set forth in SEQ ID NO.:113; and/or

(ii) the VL comprises or consists of an amino acid sequence having at least 99% identity to the amino acid sequence set forth in SEQ ID NO.:168.

Embodiment 70. The isolated antibody or antigen-binding fragment of any one of Embodiments 63-69, which is capable of inhibiting an interaction between:

(i) SARS-CoV-2 and a human DC-SIGN;

(ii) SARS-CoV-2 and a human L-SIGN;

(iii) SARS-CoV-2 and a human SIGLEC-1; or

(iv) any combination of (i)-(iii).

Embodiment 71. The isolated antibody or antigen-binding fragment of any one of Embodiments 63-70, wherein the antibody or antigen-binding fragment comprises a human antibody, a monoclonal antibody, a purified antibody, a single chain antibody, a Fab, a Fab′, a F(ab′)2, a Fv, a scFv, or a scFab.

Embodiment 72. The isolated antibody or antigen-binding fragment of any one of Embodiments 63-71, wherein the antibody or antigen-binding fragment further comprises a Fc polypeptide or a fragment thereof.

Embodiment 73. The isolated antibody or antigen-binding fragment of any one of Embodiments 63-72, which is a IgG, IgA, IgM, IgE, or IgD isotype.

Embodiment 74. The isolated antibody or antigen-binding fragment of Embodiment 72 or 73, wherein the Fc polypeptide or fragment thereof comprises:

(i) a mutation that enhances binding to a FcRn as compared to a reference Fc polypeptide that does not comprise the mutation; and/or

(ii) a mutation that enhances binding to a FcγR as compared to a reference Fc polypeptide that does not comprise the mutation.

Embodiment 75. The isolated antibody or antigen-binding fragment of Embodiment 74, wherein the mutation that enhances binding to a FcRn comprises:

-   -   (i) M428L/N434S;     -   (ii) M252Y/S254T/T256E;     -   (iii) T250Q/M428L;     -   (iv) P257I/Q311I;     -   (v) P257I/N434H;     -   (vi) D376V/N434H;     -   (vii) T307A/E380A/N434A; or     -   (viii) any combination of (i)-(vii).

Embodiment 76. The isolated antibody or antigen-binding fragment of Embodiment 75, wherein the mutation that enhances binding to FcRn comprises M428L/N434S.

Embodiment 77. The isolated antibody or antigen-binding fragment of any one of Embodiments 74-76, wherein the mutation that enhances binding to a FcγR comprises S239D, I332E, A330L, G236A, or any combination thereof.

Embodiment 78. The isolated antibody or antigen-binding fragment of Embodiment 77, wherein the mutation that enhances binding to a FcγR comprises:

(i) S239D/I332E;

(ii) S239D/A330L/I332E;

(iii) G236A/S239D/I332E; or

(iv) G236A/A330L/I332E.

Embodiment 79. The isolated antibody or antigen-binding fragment of any one of Embodiments 63-78, further comprising a CH1-CH3 that comprises or consists of the amino acid sequence set forth in SEQ ID NO.:265 or 266.

Embodiment 80. An isolated antibody, or an antigen-binding fragment thereof, comprising a heavy chain variable domain (VH) and a light chain variable domain (VL), wherein the VH comprises or consists of the amino acid sequence set forth in SEQ ID NO.:113 and the VL comprises or consists of the amino acid sequence set forth in SEQ ID NO.:168.

Embodiment 81. The isolated antibody or antigen-binding fragment of Embodiment 80, which is capable of neutralizing a SARS-CoV-2 infection:

(i) in an in vitro model of infection;

(ii) in an in vivo animal model of infection;

(iii) in a human; or

(iv) any combination of (i)-(iii).

Embodiment 82. The isolated antibody or antigen-binding fragment of Embodiment 80 or 81, which is capable of inhibiting an interaction between:

(i) SARS-CoV-2 and a human DC-SIGN;

(ii) SARS-CoV-2 and a human L-SIGN;

(iii) SARS-CoV-2 and a human SIGLEC-1; or

(iv) any combination of (i)-(iii).

Embodiment 83. The isolated antibody or antigen-binding fragment of any one of Embodiments 80-82, wherein the antibody or antigen-binding fragment further comprises a Fc polypeptide or a fragment thereof.

Embodiment 84. The isolated antibody or antigen-binding fragment of any one of Embodiments 80-83, which is a IgG, IgA, IgM, IgE, or IgD isotype.

Embodiment 85. The isolated antibody or antigen-binding fragment of any one of Embodiments 83 or 84, wherein the Fc polypeptide or fragment thereof comprises:

(i) a mutation that enhances binding to a FcRn as compared to a reference Fc polypeptide that does not comprise the mutation; and/or

(ii) a mutation that enhances binding to a FcγR as compared to a reference Fc polypeptide that does not comprise the mutation.

Embodiment 86. The isolated antibody or antigen-binding fragment of Embodiment 85, wherein the mutation that enhances binding to a FcRn comprises:

(i) M428L/N434S;

(ii) M252Y/S254T/T256E;

(iii) T250Q/M428L;

(iv) P257I/Q311I;

(v) P257I/N434H;

(vi) D376V/N434H;

(vii) T307A/E380A/N434A; or

(viii) any combination of (i)-(vii).

Embodiment 87. The isolated antibody or antigen-binding fragment of Embodiment 86, wherein the mutation that enhances binding to FcRn comprises M428L/N434S.

Embodiment 88. The isolated antibody or antigen-binding fragment of any one of Embodiments 85-87, wherein the mutation that enhances binding to a FcγR comprises S239D, I332E, A330L, G236A, or any combination thereof.

Embodiment 89. The isolated antibody or antigen-binding fragment of Embodiment 88, wherein the mutation that enhances binding to a FcγR comprises:

(i) S239D/I332E;

(ii) S239D/A330L/I332E;

(iii) G236A/S239D/I332E; or

(iv) G236A/A330L/I332E.

Embodiment 90. The isolated antibody or antigen-binding fragment of any one of Embodiments 80-89, further comprising a CH1-CH3 that comprises or consists of the amino acid sequence set forth in SEQ ID NO.:265 or 266.

Embodiment 91. An isolated antibody that comprises:

(i) a heavy chain comprising (i)(1) a VH that comprises or consists of the amino acid sequence set forth in SEQ ID NO.:113, and (i)(2) a CH1-CH3 that comprises or consists of the amino acid sequence set forth in SEQ ID NO.:173; and

(ii) a light chain comprising (ii)(1) a VL that comprises or consists of the amino acid sequence set forth in SEQ ID NO.: 168, and (ii)(2) a CL that comprises or consists of the amino acid sequence set forth in SEQ ID NO.:174.

Embodiment 92. An isolated antibody, or an antigen-binding fragment thereof, that is capable of binding to a SARS-CoV-2 surface glycoprotein (S) and inhibiting an interaction between a SARS-CoV-2 and a human DC-SIGN, a human L-SIGN, a human SIGLEC-1, or any combination thereof.

Embodiment 93. An isolated antibody that comprises:

(i) a heavy chain comprising (i)(1) a VH that comprises or consists of the amino acid sequence set forth in SEQ ID NO.:113, and (i)(2) a CH1-CH3 that comprises or consists of the amino acid sequence set forth in SEQ ID NO.:175; and

(ii) a light chain comprising (ii)(1) a VL that comprises or consists of the amino acid sequence set forth in SEQ ID NO.: 168, and (ii)(2) a CL that comprises or consists of the amino acid sequence set forth in SEQ ID NO.:174.

Embodiment 94. An isolated antibody, or an antigen-binding fragment thereof, comprising a heavy chain variable domain (VH) that comprises the complementarity determining region (CDR)H1 amino acid sequence set forth in SEQ ID NO.:106, the CDRH2 amino acid sequence set forth in SEQ ID NO.:121, and the CDRH3 amino acid sequence set forth in SEQ ID NO.:108, and a light chain variable domain (VL) that comprises the CDRL1 amino acid sequence set forth in SEQ ID NO.:169, the CDRL2 amino acid sequence set forth in SEQ ID NO.:170, and the CDRL3 amino acid sequence set forth in SEQ ID NO.:171,

wherein the antibody or antigen-binding fragment is capable of binding to a SARS-CoV-2 surface glycoprotein (S): expressed on a cell surface of a host cell; on a SARS-CoV-2 virion; or both.

Embodiment 95. The antibody or antigen-binding fragment of Embodiment 94, which is capable of neutralizing a SARS-CoV-2 infection:

(i) in an in vitro model of infection;

(ii) in an in vivo animal model of infection;

(iii) in a human; or

(iv) any combination of (i)-(iii).

Embodiment 96. The antibody or antigen-binding fragment of Embodiment 94 or 95, wherein:

(i) the NTH comprises or consists of an amino acid sequence having at least 85% identity to the amino acid sequence set forth in SEQ ID NO.:113; and/or

(ii) the VL comprises or consists of an amino acid sequence having at least 85% identity to the amino acid sequence set forth in SEQ ID NO.:168.

Embodiment 97. The antibody or antigen-binding fragment of any one of Embodiments 94-96, wherein the VH comprises or consists of the amino acid sequence set forth in SEQ ID NO.:113 and the VL comprises or consists of the amino acid sequence set forth in SEQ ID NO.:168.

Embodiment 98. The antibody or antigen-binding fragment of any one of Embodiments 94-97, which:

(i) is capable of binding to SARS-CoV-2 surface glycoprotein with greater avidity than to a SARS coronavirus S protein;

(ii) is cross-reactive against SARS-CoV-2 and SARS coronavirus;

(iii) recognizes an epitope in the SARS-CoV-2 surface glycoprotein that is not in the ACE2 RBM; or

(iv) any combination of (i)-(iii).

Embodiment 99. The antibody or antigen-binding fragment of any one of Embodiments 94-98, which is a IgG, IgA, IgM, IgE, or IgD isotype, and is preferably an IgG isotype selected from IgG1, IgG2, IgG3, and IgG4.

Embodiment 100. The antibody or antigen-binding fragment of any one of Embodiments 94-99:

(i) which is human, humanized, or chimeric;

(ii) wherein the antibody or the antigen-binding fragment comprises a human antibody, a monoclonal antibody, a purified antibody, a single chain antibody, a Fab, a Fab′, a F(ab′)2, a Fv, a scFv, or a scFab; and/or

(iii) wherein the antibody or antigen-binding fragment is a multi-specific antibody or antigen-binding fragment, wherein, optionally, the antigen-binding fragment is a bispecific antibody or antigen-binding fragment.

Embodiment 101. The antibody or antigen-binding fragment of any one of Embodiments 94-100, wherein the antibody or antigen-binding fragment further comprises a Fc polypeptide or a fragment thereof.

Embodiment 102. The antibody or antigen-binding fragment of Embodiment 101, wherein the Fc polypeptide or fragment thereof comprises:

(1) a mutation that enhances binding to a FcRn as compared to a reference Fc polypeptide that does not comprise the mutation, wherein, optionally, the mutation that enhances binding to a FcRn comprises M428L, N434S, N434H, N434A, N434S, M252Y, S254T, T256E, T250Q, P257I, Q311I, D376V, T307A, E380A, or any combination thereof, wherein, further optionally, the mutation that enhances binding to a FcRn comprises: (i) M428L/N434S; (ii) M252Y/S254T/T256E; (iii) T250Q/M428L; (iv) P257I/Q311I; (v) P257I/N434H; (vi) D376V/N434H; (vii) T307A/E380A/N434A; or (viii) any combination of (i)-(vii); and/or

(2) a mutation that enhances binding to a FcγR as compared to a reference Fc polypeptide that does not comprise the mutation, wherein, optionally, the mutation that enhances binding to a FcγR comprises S239D, I332E, A330L, G236A, or any combination thereof, wherein, further optionally, the mutation that enhances binding to a FcγR comprises: (i) S239D/I332E; (ii) S239D/A330L/I332E; (iii) G236A/S239D/I332E; or (iv) G236A/A330L/I332E.

Embodiment 103. The antibody or antigen-binding fragment of Embodiment 102, wherein the mutation that enhances binding to a FcRn comprises M428L/N434S and/or the mutation that enhances binding to a FcγR comprises G236A/A330L/I332E.

Embodiment 104. The antibody or antigen-binding fragment of any one of Embodiments 94-103, comprising:

(i) a CH1-CH3 having 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99%, or 100% identity to SEQ ID NO.:173 or 175; and/or

(ii) a CL comprising an amino acid sequence having 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99%, or 100% identity to the amino acid sequence of SEQ ID NO.:174.

Embodiment 105. The antibody or antigen-binding fragment of any one of Embodiments 94-104, which comprises a mutation that alters glycosylation of the antibody or antigen-binding fragment, wherein the mutation that alters glycosylation of the antibody or antigen-binding fragment comprises N297A, N297Q, or N297G, and/or wherein the antibody or antigen-binding fragment is aglycosylated and/or afucosylated.

Embodiment 106. The antibody or antigen-binding fragment of any one of Embodiments 94-4105, wherein the antibody or antigen-binding fragment binds to a SARS-CoV-2 surface glycoprotein or an RBD thereof with a KD of less than about 4.5×10⁻⁹M, less than about 5×10⁻⁹ M, less than about 1×10⁻¹⁰ M, less than about 5×10⁻¹⁰ M, less than about 1×10⁻¹¹ M, less than about 5×10⁻¹¹ M, or less than about 1×10⁻¹² M, as measured by biolayer interferometry, wherein, optionally, the antibody or antigen-binding fragment binds to the SARS-CoV-2 surface glycoprotein with a KD of less than 1×10⁻¹²M, as measured by biolayer interferometry (e.g., by immobilizing the antibody or antigen-binding fragment on sensors and dipping the sensors into wells containing different concentrations of SARS-CoV-2 or RBD, recording kinetics of antibody binding during the association phase, after which the sensors are dipped into buffer without antibody to observe kinetics of antibody detaching from the SARS-CoV-2 or RBD during the dissociation phase. Protein A biosensors (Pall ForteBio) can be used to immobilize recombinant antibodies at 2.7 ug/ml for 1 minute, after a hydration step for 10 minutes with Kinetics Buffer (KB; 0.01% endotoxin-free BSA, 0.002{circumflex over ( )} Tween-20, 0.005% NaN3 in PBS). Association curves can be recorded for 5 minutes by incubating the antibody-coated sensors with different concentrations of SARS-CoV-1 RBD (Sino Biological) or SARS-CoV-2 RBD (produced in house in Expi-CHO cells; residues 331-550 of spike from BetaCoV/Wuhan-Hu-1/2019, accession number MN908947). SARS-CoV-2 or RBD concentration tested can be 10 ug/ml, then 1:2.5 serially diluted. Dissociation can be recorded for 9 minutes by moving the sensors to wells containing KB. Affinities, represented by KD values, can be calculated using a global fit model (Octet). Octet Red96 (ForteBio) equipment was used).

Embodiment 107. The antibody or antigen-binding fragment of any one of Embodiments 94-106, wherein the antibody or antigen-binding fragment is capable of inducing antibody-dependent cell-mediated cytotoxicity (ADCC) and/or antibody dependent cellular phagocytosis (ADCP) against a target cell infected by a SARS-CoV-2,

wherein, optionally, the inducing ADCC comprises activating a Natural Killer cell that comprises a V158 FcγRIIIa variant, a Natural Killer cell that comprises a F158 FcγRIIIa variant, or both, and/or the inducing ADCP comprises engaging a FcγRIIa expressed on the surface of a phagocytic cell, such as a monocyte, a macrophage, or a dendritic cell.

Embodiment 108. The antibody or antigen-binding fragment of any one of Embodiments 94-107, wherein the antibody or antigen-binding fragment is a Fab and the Fab is capable of binding to a SARS-CoV-2 surface glycoprotein with a KD of 2.0×10⁻⁹M or less, 1.9×10⁻⁹M or less, or 1.8×10⁻⁹M or less, as measured by biolayer interferometry.

Embodiment 109. The antibody or antigen-binding fragment of any one of Embodiments 94-108, wherein the antibody or antigen-binding fragment is capable of neutralizing infection by the SARS-CoV-2 and does not compete with a human ACE2 for binding to the SARS-CoV-2 surface glycoprotein.

Embodiment 110. An antibody, or an antigen-binding fragment thereof, that competes for binding to a SARS-CoV-2 surface glycoprotein with the antibody or antigen-binding fragment of any one of Embodiments 94-109.

Embodiment 111. The antibody or antigen-binding fragment of any one of Embodiments 94-110, which is capable of binding to the SARS-CoV-2 surface glycoprotein when the SARS-CoV-2 surface glycoprotein is comprised in a prefusion trimer.

Embodiment 112. The antibody or antigen-binding fragment of any one of Embodiments 94-111, which is capable of binding to a Receptor Binding Domain (RBD) of the SARS-CoV-2 surface glycoprotein when the RBD is glycosylated and/or when the RBD is deglycosylated, wherein the binding is determined using surface plasmon resonance (SPR), wherein, optionally:

(1) the SPR is performed using a Biacore T200 instrument using a single-cycle kinetics approach, further optionally with a 3 minute injection period and a 20 minute dissociation period;

(2) the antibody or antigen-binding fragment is captured on a surface;

(3) the RBD is present at a concentration of 0.8 nM, 3.1 nM, 12.5 nM, 50 nM, or 200 nM;

(4) the antibody or antigen-binding fragment binds to the glycosylated RBD with a KD of about about 0.6 nM, about 0.5 nM, about 0.4 nM, or about 0.3 nM, or with a KD of 0.3 nM±0.05 nM, or with a KD of 0.4 nM±0.05 nM, or with a KD of 0.45 nM±0.05 nM, or with a KD of 0.5 nM±0.05 nM, or with a KD of 0.6 nM±0.05 nM; and/or

(5) the antibody or antigen-binding fragment binds to the deglycosylated RBD with a KD of about 1.6 nM, about 1.5 nM, about 1.4 nM, about 1.3 nM, about 1.2 nM, about 1.1 nM, about 1.0.

Embodiment 113. The antibody or antigen-binding fragment of any one of Embodiments 94-112, which is capable of neutralizing an infection by the SARS-CoV-2 in a human lung cell, wherein, optionally, the human lung cell comprises a Calu-3 cell, wherein, further optionally, the antibody or antigen-binding fragment has a neutralization IC50 of about 97 ng/mL.

Embodiment 114. The antibody or antigen-binding fragment of any one of Embodiments 94-113, which is capable of binding to a human complement component C1q, wherein, optionally, binding to the C1q is determined using biolayer interferometry (BLI), such as using an Octet instrument.

Embodiment 115. The antibody or antigen-binding fragment of any one of Embodiments 94-114, which is capable of inhibiting SARS-CoV-2 surface glycoprotein-mediated cell-cell fusion.

Embodiment 116. The antibody or antigen-binding fragment of any one of Embodiments 94-115, which does not cause antibody-mediated enhancement of SARS-CoV-2 replication in a human donor-derived peripheral blood mononuclear cell (PBMC) or a dendritic cell.

Embodiment 117. The antibody or antigen-binding fragment of any one of Embodiments 94-116, which is capable of inhibiting an interaction between:

(i) SARS-CoV-2 and a human DC-SIGN;

(ii) SARS-CoV-2 and a human L-SIGN;

(iii) SARS-CoV-2 and a human SIGLEC-1; or

(iv) any combination of (i)-(iii).

Embodiment 118. The antibody or antigen-binding fragment of any one of Embodiments 94-117, which is capable of binding to a surface glycoprotein of:

(i) a SARS-CoV-2 Wuhan-Hu-1 (SEQ ID NO.:165);

(ii) a SARS-CoV-2 B.1.1.7;

(iii) a SARS-CoV-2 B.1.351;

(iv) a SARS-CoV-2 comprising any one or more of the following substitution mutations relative to SEQ ID NO.:165: N501Y; S477N; N439K; L452R; E484K; Y453F; A520S; K417N; K417V; S494P; N501T; 5477R; V367F; P384L; A522S; A522V; V382L; P330S; T478I; S477I; P479S; or

(v) any combination of (i)-(iv).

Embodiment 119. The antibody or antigen-binding fragment of any one of Embodiments 94-118, wherein the antibody or antigen-binding fragment is capable of neutralizing infection by the SARS-CoV-2 with an IC50 of 3.0 nM, 3.1 nM, 3.2 nM, 3.3 nM, 3.4 nM, 3.5 nM, 3.6 nM, 3.7 nM, 3.8 nM, 3.9 nM, or 4.0 nM.

Embodiment 120. The antibody or antigen-binding fragment of any one of Embodiments 94-119, comprising:

(i) a heavy chain comprising (i)(1) a VH that comprises or consists of the amino acid sequence set forth in SEQ ID NO.:113, and (i)(2) a CH1-CH3 that comprises or consists of the amino acid sequence set forth in SEQ ID NO.:173; and

(ii) a light chain comprising (ii)(1) a VL that comprises or consists of the amino acid sequence set forth in SEQ ID NO.: 168, and (ii)(2) a CL that comprises or consists of the amino acid sequence set forth in SEQ ID NO.:174.

Embodiment 121. The antibody or antigen-binding fragment of any one of Embodiments 94-120, comprising:

(i) a heavy chain comprising (i)(1) a VH that comprises or consists of the amino acid sequence set forth in SEQ ID NO.:113, and (i)(2) a CH1-CH3 that comprises or consists of the amino acid sequence set forth in SEQ ID NO.:175; and

(ii) a light chain comprising (ii)(1) a VL that comprises or consists of the amino acid sequence set forth in SEQ ID NO.: 168, and (ii)(2) a CL that comprises or consists of the amino acid sequence set forth in SEQ ID NO.:174.

Embodiment 122. The antibody or antigen-binding fragment of any one of Embodiments 94-121, comprising a CH1-CH3 that comprises or consists of the amino acid sequence set forth in SEQ ID NO.:265 or 266.

Embodiment 123. An isolated polynucleotide encoding the antibody or antigen-binding fragment of any one of Embodiments 1-122, or encoding a VH, a heavy chain, a VL, and/or a light chain of the antibody or the antigen-binding fragment.

Embodiment 124. The isolated polynucleotide of Embodiment 123, wherein the polynucleotide comprises deoxyribonucleic acid (DNA) or ribonucleic acid (RNA), wherein the RNA optionally comprises messenger RNA (mRNA).

Embodiment 125. The isolated polynucleotide of Embodiment 123 or 124, which is codon-optimized for expression in a host cell.

Embodiment 126. The isolated polynucleotide of any one of Embodiments 123-125, comprising a polynucleotide having at least 50% identity to the polynucleotide sequence according to any one or more of SEQ ID NOs.:186-189, 191-192, 238, 247, 248-255 and 257-262.

Embodiment 127. The isolated polynucleotide of any one of Embodiments 123-126, comprising the polynucleotide sequence set forth in any one or more of SEQ ID NOs.:249, 250, and 257-262.

Embodiment 128. A recombinant vector comprising the polynucleotide of any one of Embodiments 123-127.

Embodiment 129. A host cell comprising the polynucleotide of any one of Embodiments 123-127 and/or the vector of Embodiment 128, wherein the polynucleotide is heterologous to the host cell.

Embodiment 130. A human B cell comprising the polynucleotide of any one of Embodiments 123-129, wherein polynucleotide is heterologous to the human B cell and/or wherein the human B cell is immortalized.

Embodiment 131. A composition comprising:

(i) the antibody or antigen-binding fragment of any one of Embodiments 1-122;

(ii) the polynucleotide of any one of Embodiments 123-127;

(iii) the recombinant vector of Embodiment 128;

(iv) the host cell of Embodiment 129; and/or

(v) the human B cell of Embodiment 130, and a pharmaceutically acceptable excipient, carrier, or diluent.

Embodiment 132. The composition of Embodiment 131, comprising two or more antibodies or antigen-binding fragments of any one of Embodiments 1-122.

Embodiment 133. The composition of Embodiment 132, comprising:

(i) a first antibody or antigen-binding fragment, comprising a VH comprising or consisting of the amino acid sequence set forth in SEQ ID NO.:79 and a VL comprising or consisting of the amino acid sequence set forth in SEQ ID NO.:83; and

(ii) a second antibody or antigen-binding fragment comprising, a VH comprising or consisting of the amino acid sequence set forth in SEQ ID NO.:105 and a VL comprising of consisting of the amino acid sequence set forth in SEQ ID NO.:168.

Embodiment 134. The composition of Embodiment 132, comprising:

(i) a first antibody or antigen-binding fragment comprising a heavy chain variable domain (VH) comprising a CDRH1, a CDRH2, and a CDRH3, and a light chain variable domain (VL) comprising a CDRL1, a CDRL2, and a CDRL3, wherein the CDRH1, CDRH2, and CDRH3 comprise or consist of the amino acid sequences set forth in SEQ ID NOs.:80-82, respectively, and the CDRL1, CDRL2, and CDRL3 comprise or consist of the amino acid sequences set forth in SEQ ID NOs.:84-86, respectively; and

(ii) a second antibody or antigen-binding fragment comprising a heavy chain variable domain (VH) comprising a CDRH1, a CDRH2, and a CDRH3, and a light chain variable domain (VL) comprising a CDRL1, a CDRL2, and a CDRL3, wherein the CDRH1, CDRH2, and CDRH3 comprise or consist of the amino acid sequences set forth in SEQ ID NOs.:106-108, respectively, and the CDRL1, CDRL2, and CDRL3 comprise or consist of the amino acid sequences set forth in SEQ ID NOs.:169-171, respectively.

Embodiment 135. The composition of Embodiment 132, comprising:

(i) a first antibody or antigen-binding fragment, comprising a VH comprising or consisting of the amino acid sequence set forth in SEQ ID NO.:178 and a VL comprising or consisting of the amino acid sequence set forth in SEQ ID NO.:182 or SEQ ID NO.:190; and

(ii) a second antibody or antigen-binding fragment comprising, a VH comprising or consisting of the amino acid sequence set forth in SEQ ID NO.:105 and a VL comprising of consisting of the amino acid sequence set forth in SEQ ID NO.:168.

Embodiment 136. The composition of Embodiment 135, comprising:

(i) a first antibody or antigen-binding fragment comprising a heavy chain variable domain (VH) comprising a CDRH1, a CDRH2, and a CDRH3, and a light chain variable domain (VL) comprising a CDRL1, a CDRL2, and a CDRL3, wherein the CDRH1, CDRH2, and CDRH3 comprise or consist of the amino acid sequences set forth in SEQ ID NOs.:179-181, respectively, and the CDRL1, CDRL2, and CDRL3 comprise or consist of the amino acid sequences set forth in SEQ ID NOs.:183-185, respectively; and

(ii) a second antibody or antigen-binding fragment comprising a heavy chain variable domain (VH) comprising a CDRH1, a CDRH2, and a CDRH3, and a light chain variable domain (VL) comprising a CDRL1, a CDRL2, and a CDRL3, wherein the CDRH1, CDRH2, and CDRH3 comprise or consist of the amino acid sequences set forth in SEQ ID NOs.:106-108, respectively, and the CDRL1, CDRL2, and CDRL3 comprise or consist of the amino acid sequences set forth in SEQ ID NOs.:169-171, respectively.

Embodiment 137. The composition of Embodiment 132, comprising:

(i) a first antibody or antigen-binding fragment comprising a VH comprising or consisting of the amino acid sequence set forth in SEQ ID NO.:178 and a VL comprising or consisting of the amino acid sequence set forth in SEQ ID NO.:182 or SEQ ID NO.:190; and

(ii) a second antibody or antigen-binding fragment comprising a VH comprising or consisting of the amino acid sequence set forth in SEQ ID NO.:63 and a VL comprising or consisting of the amino acid sequence set forth in SEQ ID NO.:67, any one of SEQ ID NOs.:71-71, or any one of SEQ ID NOs:75-76.

Embodiment 138. The composition of Embodiment 132, comprising:

(i) a first antibody or antigen-binding fragment comprising a heavy chain variable domain (VH) comprising a CDRH1, a CDRH2, and a CDRH3, and a light chain variable domain (VL) comprising a CDRL1, a CDRL2, and a CDRL3, wherein the CDRH1, CDRH2, and CDRH3 comprise or consist of the amino acid sequences set forth in SEQ ID NOs.:179-181, respectively, and the CDRL1, CDRL2, and CDRL3 comprise or consist of the amino acid sequences set forth in SEQ ID NOs.:183-185, respectively; and

(ii) a second antibody or antigen-binding fragment comprising a heavy chain variable domain (VH) comprising a CDRH1, a CDRH2, and a CDRH3, and a light chain variable domain (VL) comprising a CDRL1, a CDRL2, and a CDRL3, wherein the CDRH1, CDRH2, and CDRH3 comprise or consist of the amino acid sequences set forth in SEQ ID NOs.:64-66, respectively, the CDRL1 comprises or consists of the amino acid sequences set forth in any one of SEQ ID NO.:68, SEQ ID NO.:73, or SEQ ID NO.:74, the CDRL2 comprises or consists of the amino acid sequences set forth in SEQ ID NO.:69, and the CDRL3 comprises or consists of the amino acid sequences set forth in SEQ ID NO.:70, SEQ ID NO.:77, or SEQ ID NO.:78.

Embodiment 139. A composition comprising (i) the antibody or antigen-binding fragment of Embodiment 8 or 9 and (ii) the antibody or antigen-binding fragment of Embodiment 10 or 11, wherein the composition is capable of neutralizing a SARS-CoV-2 infection with an IC50 of about 0.07 to about 0.08 μg/ml.

Embodiment 140. A composition comprising the polynucleotide of any one of Embodiments 123-127 encapsulated in a carrier molecule, wherein the carrier molecule optionally comprises a lipid, a lipid-derived delivery vehicle, such as a liposome, a solid lipid nanoparticle, an oily suspension, a submicron lipid emulsion, a lipid microbubble, an inverse lipid micelle, a cochlear liposome, a lipid microtubule, a lipid microcylinder, lipid nanoparticle (LNP), or a nanoscale platform.

Embodiment 141. A method of treating a SARS-CoV-2 infection in a subject, the method comprising administering to the subject an effective amount of:

(i) the antibody or antigen-binding fragment of any one of Embodiments 1-122;

(ii) the polynucleotide of any one of Embodiments 123-127;

(iii) the recombinant vector of Embodiment 128;

(iv) the host cell of Embodiment 129;

(v) the human B cell of Embodiment 130; and/or

(vi) the composition of any one of Embodiments 131-140.

Embodiment 142. A method of inhibiting a SARS-CoV-2 infection in a subject, the method comprising administering to the subject an effective amount of:

(i) the antibody or antigen-binding fragment of any one of Embodiments 1-122;

(ii) the polynucleotide of any one of Embodiments 123-127;

(iii) the recombinant vector of Embodiment 128;

(iv) the host cell of Embodiment 129;

(v) the human B cell of Embodiment 130; and/or

(vi) the composition of any one of Embodiments 131-140.

Embodiment 143. The antibody or antigen-binding fragment of any one of Embodiments 1-122, the polynucleotide of any one of Embodiments 123-127, the recombinant vector of Embodiment 128, the host cell of Embodiment 129, the human B cell of Embodiment 130, and/or the composition of any one of Embodiments 131-140 for use in a method of treating a SARS-CoV-2 infection in a subject.

Embodiment 144. The antibody or antigen-binding fragment of any one of Embodiments 1-122, the polynucleotide of any one of Embodiments 123-127, the recombinant vector of Embodiment 128, the host cell of Embodiment 129, the human B cell of Embodiment 130, and/or the composition of any one of Embodiments 131-140 for use in a method of inhibiting a SARS-CoV-2 infection in a subject.

Embodiment 145. The antibody or antigen-binding fragment of any one of Embodiments 1-122, the polynucleotide of any one of Embodiments 123-127, the recombinant vector of Embodiment 128, the host cell of Embodiment 129, the human B cell of Embodiment 130, and/or the composition of any one of Embodiments 131-140, for use in the preparation of a medicament for the treatment of a SARS-CoV-2 infection in a subject.

Embodiment 146. A method for in vitro diagnosis of a SARS-CoV-2 infection, the method comprising:

(i) contacting a sample from a subject with an antibody or antigen-binding fragment of any one of Embodiments 1-122; and

(ii) detecting a complex comprising an antigen and the antibody, or comprising an antigen and the antigen binding fragment.

Embodiment 147. The method of Embodiment 146, wherein the sample comprises blood isolated from the subject.

Embodiment 148. A combination or composition comprising:

(i) an antibody or antigen-binding fragment comprising

-   -   (i)(a) a CDRH1 amino acid sequence GYPFTSYG, a CDRH2 amino acid         sequence ISTYNGNT or ISTYQGNT, a CDRH3 amino acid sequence         ARDYTRGAWFGESLIGGFDN; a CDRL1 amino acid sequence or QTVSSTS, a         CDRL2 amino acid sequence GAS, and a CDRL3 amino acid sequence         QHDTSLT; or     -   (i)(b) a VH amino acid sequence comprising or consisting of

QVQLVQSGAEVKKPGASVKVSCKASGYPFTSYGISWVRQAPGQGLEWMGWI STYNGNTNYAQKFQGRVTMTTDTSTTTGYMELRRLRSDDTAVYYCARDYTR GAWFGESLIGGFDNWGQGTLVTVSS

-   -   or comprising or consisting of

QVQLVQSGAEVKKPGASVKVSCKASGYPFTSYGISWVRQAPGQGLEWMGWI STYQGNTNYAQKFQGRVTMTTDTSTTTGYMELRRLRSDDTAVYYCARDYTR GAWFGESLIGGFDNWGQGTLVTVSS,

-   -   and a VL amino acid sequence comprising or consisting of

EIVLTQSPGTLSLSPGERATLSCRASQTVSSTSLAWYQQKPGQAPRLLIYG ASSRATGIPDRFSGSGSGTDFTLTISRLEPEDFAVYYCQQHDTSLTFGGGT KVEIK;

-   -   and

(ii) an antibody or antigen-binding fragment comprising:

-   -   (ii)(a) VH and VL amino acid sequences according to SEQ ID         NOs.:79 and 83, respectively;     -   (ii)(b) CDRH1, CDRH2, CDRH3, CDRL1, CDRL2, and CDRL3 amino acid         sequences according to SEQ ID NOS.:80-82 and 84-86,         respectively;     -   (ii)(c) VH and VL amino acid sequences according to SEQ ID         NOs.:178 or 194 or 196 or 198 or 200 or 202 and 182 or 190,         respectively; or     -   (ii)(d) CDRH1, CDRH2, CDRH3, CDRL1, CDRL2, and CDRL3 amino acid         sequences according to SEQ ID NOs.:179 or 195, 180 or 197 or         199, 181, 201 or 203, and 183-185, respectively.

Embodiment 149. A method of preventing or treating or neutralizing a coronavirus infection in a subject, the method comprising administering to the subject the combination or composition of Embodiment 148, wherein, optionally, the antibody or antigen binding fragment of (i) and the antibody or antigen binding fragment of (ii) are administered concurrently, simultaneously, or consecutively.

Embodiment 150. A method of preventing or treating or neutralizing a coronavirus infection in a subject, the method comprising administering to a subject who has received a first antibody or antigen binding fragment comprising:

-   -   (a) VH and VL amino acid sequences according to SEQ ID NOs.:79         and 83, respectively; or     -   (b) CDRH1, CDRH2, CDRH3, CDRL1, CDRL2, and CDRL3 amino acid         sequences according to SEQ ID NOs.:80-82 and 84-86,         respectively;         and a second antibody or antigen binding fragment comprising:     -   (a) a VH amino acid sequence according to SEQ ID NO.:105 or 113,         and a VL amino acid sequence according to SEQ ID NO: 168; or     -   (b) CDRH1, CDRH2, and CDRH3 amino acids according to SEQ ID         NOs.: 106-108, respectively, or SEQ ID NOs.:106, 121, and 108,         respectively, and CDRL1, CDRL2, and CDRL3 amino acid sequences         according to SEQ ID NOs.:169-171, respectively.

Embodiment 151. A method of preventing or treating or neutralizing a coronavirus infection in a subject, the method comprising administering to a subject who has received a first antibody or antigen binding fragment comprising:

(a) a VH amino acid sequence according to SEQ ID NOs.:105 or 113, and a VL amino acid sequence according to SEQ ID NO.:168; or

(b) CDRH1, CDRH2, and CDRH3 amino acids according to SEQ ID NOs.: 106-108, respectively, or SEQ ID NOs.:106, 121, and 108, respectively, and CDRL1, CDRL2, and CDRL3 amino acid sequences according to SEQ ID NOS.:169-171, respectively;

a second antibody or antigen binding fragment comprising:

-   -   (a) VH and VL amino acid sequences according to SEQ ID NOs.:79         and 83, respectively; or     -   (b) CDRH1, CDRH2, CDRH3, CDRL1, CDRL2, and CDRL3 amino acid         sequences according to SEQ ID NOS.:80-82 and 84-86,         respectively.

Embodiment 152. A method of preventing or treating or neutralizing a coronavirus infection in a subject, the method comprising administering to a subject who has received a first antibody or antigen binding fragment comprising:

-   -   (a) VH and VL amino acid sequences according to SEQ ID NOs.:178         or 194 or 196 or 198 or 200 or 202 and 182 or 190, respectively;         or

(b) CDRH1, CDRH2, CDRH3, CDRL1, CDRL2, and CDRL3 amino acid sequences according to SEQ ID NOS.:179 or 195, 180 or 197 or 199, 181 201 or 203, and 183-185, respectively;

-   -   a second antibody or antigen binding fragment comprising:         -   (a) a VH amino acid sequence according to SEQ ID NOs.:105 or             113, and a VL amino acid sequence according to SEQ ID NO:             168; or         -   (b) CDRH1, CDRH2, and CDRH3 amino acids according to SEQ ID             NOs.: 106-108, respectively, or SEQ ID NOs.: 106, 121, and             108, respectively, and CDRL1, CDRL2, and CDRL3 amino acid             sequences according to SEQ ID NOS.:169-171, respectively.

Embodiment 153. A method of preventing or treating or neutralizing a coronavirus infection in a subject, the method comprising administering to a subject who has received a first antibody or antigen binding fragment comprising:

-   -   (a) a VH amino acid sequence according to SEQ ID NOs.:105 or         113, and a VL amino acid sequence according to SEQ ID NO: 168;         or     -   (b) CDRH1, CDRH2, and CDRH3 amino acids according to SEQ ID         NOs.: 106-108, respectively, or SEQ ID NOs.: 106, 121, and 108,         respectively, and CDRL1, CDRL2, and CDRL3 amino acid sequences         according to SEQ ID NOS.:169-171, respectively;     -   a second antibody or antigen binding fragment comprising:         -   (a) VH and VL amino acid sequences according to SEQ ID             NOs.:178 or 194 or 196 or 198 or 200 or 202 and 182 or 190,             respectively; or         -   (b) CDRH1, CDRH2, CDRH3, CDRL1, CDRL2, and CDRL3 amino acid             sequences according to SEQ ID NOS.:179 or 195, 180 or 197 or             199, 181 201 or 203, and 183-185, respectively.

TABLE 2 Sequences SEQ Sequence ID Description NO. Sequence SARS-CoV-2   1 QVQLVQSGAEVKKPGASVKVSCKASGYTFT S300-v1 mAb DYYIHWVRQAPGQGPEWLGWVNGYSGATR VH (aa) YAQKYQGRVTMTRDTSISTAYMQLSRLRPDD TAVYYCARDRPSHEWAMYFFDNWGQGTLV TVSS SARS-CoV-2   2 GYTFTDYY S300-v1 mAb CDRH1 (aa) SARS-CoV-2   3 VNGYSGAT S300-v1 mAb CDRH2 (aa) SARS-CoV-2   4 ARDRPSHEWAMYFFDN S300-v1 mAb CDRH3 (aa) SARS-CoV-2   5 QIVLTQSPGTLSLSPGERATLSCRASQSVPSSC S300-v1 mAb LAWYQQKPGQAPRLLIYGASGRATGIPDRFS VL (Vκ) (aa) GSGSGTDFTLTIRRLEPEDFAVYYCQQYGSSP PLTFGGGTKVEIK SARS-CoV-2   6 QSVPSSC S300-v1 mAb CDRL1 (aa) SARS-CoV-2   7 GAS S300-v1 mAb CDRL2 (aa) SARS-CoV-2   8 QQYGSSPPLT S300-v1 mAb CDRL3 (aa) SARS-CoV-2   9 QVQLVQSGAEVKKPGASVKVSCKASGYTFT S300-v1.1 DYYIHWVRQAPGQGPEWLGWVQGYSGATR mAb VH (aa) YAQKYQGRVTMTRDTSISTAYMQLSRLRPDD TAVYYCARDRPSHEWAMYFFDNWGQGTLV TVSS SARS-CoV-2  10 QVQLVQSGAEVKKPGASVKVSCKASGYTFT S300-v1.2 DYYIHWVRQAPGQGPEWLGWVNAYSGATR mAb VH (aa) YAQKYQGRVTMTRDTSISTAYMQLSRLRPDD TAVYYCARDRPSHEWAMYFFDNWGQGTLV TVSS SARS-CoV-2  11 QVQLVQSGAEVKKPGASVKVSCKASGYTFT S300-v1.3 DYYIHWVRQAPGQGPEWLGWVNSYSGATR mAb VH (aa) YAQKYQGRVTMTRDTSISTAYMQLSRLRPDD TAVYYCARDRPSHEWAMYFFDNWGQGTLV TVSS SARS-CoV-2  12 QVQLVQSGAEVKKPGASVKVSCKASGYTFT S300-v1.4 DYYIHWVRQAPGQGPEWLGWVNPYSGATR mAb VH (aa) YAQKYQGRVTMTRDTSISTAYMQLSRLRPDD TAVYYCARDRPSHEWAMYFFDNWGQGTLV TVSS SARS-CoV-2  13 QVQLVQSGAEVKKPGASVKVSCKASGYTFT S300-v1.5 DYYIHWVRQAPGQGPEWLGWVNQYSGATR mAb VH (aa) YAQKYQGRVTMTRDTSISTAYMQLSRLRPDD TAVYYCARDRPSHEWAMYFFDNWGQGTLV TVSS SARS-CoV-2  14 QVQLVQSGAEVKKPGASVKVSCKASGYTFT S300-v1.6 DYYIHWVRQAPGQGPEWLGWVLGYSGATR mAb VH (aa) YAQKYQGRVTMTRDTSISTAYMQLSRLRPDD TAVYYCARDRPSHEWAMYFFDNWGQGTLV TVSS SARS-CoV-2  15 QVQLVQSGAEVKKPGASVKVSCKASGYTFT S300-v1.7 DYYIHWVRQAPGQGPEWLGWVTGYSGATR mAb VH (aa) YAQKYQGRVTMTRDTSISTAYMQLSRLRPDD TAVYYCARDRPSHEWAMYFFDNWGQGTLV TVSS SARS-CoV-2  16 VQGYSGAT S300-v1.1 mAb CDRH2 (aa) SARS-CoV-2  17 VNAYSGAT S300-v1.2 mAb CDRH2 (aa) SARS-CoV-2  18 VNSYSGAT S300-v1.3 mAb CDRH2 (aa) SARS-CoV-2  19 VNPYSGAT S300-v1.4 mAb CDRH2 (aa) SARS-CoV-2  20 VNQYSGAT S300-v1.5 mAb CDRH2 (aa) SARS-CoV-2  21 VLGYSGAT S300-v1.6 mAb CDRH2 (aa) SARS-CoV-2  22 VTGYSGAT S300-v1.7 mAb CDRH2 (aa) SARS-CoV-2  23 QVQLVQSGAEVKKPGASVKVSCKASGYTFT S300-v1.8 DYYIHWVRQAPGQGPEWLGWVNGYSGATR mAb VH (aa) YAQKYQGRVTMTRDTSISTAYMQLSRLRPDD TAVYYCARDRPSHEFAMYFFDNWGQGTLV TVSS SARS-CoV-2  24 QVQLVQSGAEVKKPGASVKVSCKASGYTFT S300-v1.9 DYYIHWVRQAPGQGPEWLGWVNGYSGATR mAb VH (aa) YAQKYQGRVTMTRDTSISTAYMQLSRLRPDD TAVYYCARDRPSHEYAMYFFDNWGQGTLV TVSS SARS-CoV-2  25 ARDRPSHEFAMYFFDN S300-v1.8 mAb CDRH3 (aa) SARS-CoV-2  26 ARDRPSHEYAMYFFDN S300-v1.9 mAb CDRH3 (aa) SARS-CoV-2  27 QVQLVQSGAEVKKPGASVKVSCKASGYTFT S300-v2 mAb DYYIHWVRQAPGQGPEWLGFVNGYSGATRY VH (aa) AQKYQGRVTMTRDTSISTAYMQLSRLRPDDT AVYYCARDRPSHEWAMYFFDNWGQGTLVT VSS SARS-CoV-2  28 QVQLVQSGAEVKKPGASVKVSCKASGYTFT S300-v2.1 DYYIHWVRQAPGQGPEWLGFVQGYSGATRY mAb VH (aa) AQKYQGRVTMTRDTSISTAYMQLSRLRPDDT AVYYCARDRPSHEWAMYFFDNWGQGTLVT VSS SARS-CoV-2  29 QVQLVQSGAEVKKPGASVKVSCKASGYTFT S300-v2.2 DYYIHWVRQAPGQGPEWLGFVNAYSGATRY mAb VH (aa) AQKYQGRVTMTRDTSISTAYMQLSRLRPDDT AVYYCARDRPSHEWAMYFFDNWGQGTLVT VSS SARS-CoV-2  30 QVQLVQSGAEVKKPGASVKVSCKASGYTFT S300-v2.3 DYYIHWVRQAPGQGPEWLGFVNSYSGATRY mAb VH (aa) AQKYQGRVTMTRDTSISTAYMQLSRLRPDDT AVYYCARDRPSHEWAMYFFDNWGQGTLVT VSS SARS-CoV-2  31 QVQLVQSGAEVKKPGASVKVSCKASGYTFT S300-v2.4 DYYIHWVRQAPGQGPEWLGFVNPYSGATRY mAb VH (aa) AQKYQGRVTMTRDTSISTAYMQLSRLRPDDT AVYYCARDRPSHEWAMYFFDNWGQGTLVT VSS SARS-CoV-2  32 QVQLVQSGAEVKKPGASVKVSCKASGYTFT S300-v2.5 DYYIHWVRQAPGQGPEWLGFVNQYSGATRY mAb VH (aa) AQKYQGRVTMTRDTSISTAYMQLSRLRPDDT AVYYCARDRPSHEWAMYFFDNWGQGTLVT VSS SARS-CoV-2  33 QVQLVQSGAEVKKPGASVKVSCKASGYTFT S300-v2.6 DYYIHWVRQAPGQGPEWLGFVLGYSGATRY mAb VH (aa) AQKYQGRVTMTRDTSISTAYMQLSRLRPDDT AVYYCARDRPSHEWAMYFFDNWGQGTLVT VSS SARS-CoV-2  34 QVQLVQSGAEVKKPGASVKVSCKASGYTFT S300-v2.7 DYYIHWVRQAPGQGPEWLGFVTGYSGATRY mAb VH (aa) AQKYQGRVTMTRDTSISTAYMQLSRLRPDDT AVYYCARDRPSHEWAMYFFDNWGQGTLVT VSS SARS-CoV-2  35 QVQLVQSGAEVKKPGASVKVSCKASGYTFT S300-v2.8 DYYIHWVRQAPGQGPEWLGFVNGYSGATRY mAb VH (aa) AQKYQGRVTMTRDTSISTAYMQLSRLRPDDT AVYYCARDRPSHEFAMYFFDNWGQGTLVT VSS SARS-CoV-2  36 QVQLVQSGAEVKKPGASVKVSCKASGYTFT S300-v2.9 DYYIHWVRQAPGQGPEWLGFVNGYSGATRY mAb VH (aa) AQKYQGRVTMTRDTSISTAYMQLSRLRPDDT AVYYCARDRPSHEYAMYFFDNWGQGTLVT VSS SARS-CoV-2  37 QVQLVQSGAEVKKPGASVKVSCKASGYTFT S300-v3 mAb DYYIHWVRQAPGQGPEWLGYVNGYSGATR VH (aa) YAQKYQGRVTMTRDTSISTAYMQLSRLRPDD TAVYYCARDRPSHEWAMYFFDNWGQGTLV TVSS SARS-CoV-2  38 QVQLVQSGAEVKKPGASVKVSCKASGYTFT S300-v3.1 DYYIHWVRQAPGQGPEWLGYBR mAb VH (aa) YAQKYQGRVTMTRDTSISTAYMQLSRLRPDD TAVYYCARDRPSHEWAMYFFDNWGQGTLV TVSS SARS-CoV-2  39 QVQLVQSGAEVKKPGASVKVSCKASGYTFT S300-v3.2 DYYIHWVRQAPGQGPEWLGYVNAYSGATR mAb VH (aa) YAQKYQGRVTMTRDTSISTAYMQLSRLRPDD TAVYYCARDRPSHEWAMYFFDNWGQGTLV TVSS SARS-CoV-2  40 QVQLVQSGAEVKKPGASVKVSCKASGYTFT S300-v3.3 DYYIHWVRQAPGQGPEWLGYVNSYSGATRY mAb VH (aa) AQKYQGRVTMTRDTSISTAYMQLSRLRPDDT AVYYCARDRPSHEWAMYFFDNWGQGTLVT VSS SARS-CoV-2  41 QVQLVQSGAEVKKPGASVKVSCKASGYTFT S300-v3.4 DYYIHWVRQAPGQGPEWLGYVNPYSGATRY mAb VH (aa) AQKYQGRVTMTRDTSISTAYMQLSRLRPDDT AVYYCARDRPSHEWAMYFFDNWGQGTLVT VSS SARS-CoV-2  42 QVQLVQSGAEVKKPGASVKVSCKASGYTFT S300-v3.5 DYYIHWVRQAPGQGPEWLGYVNQYSGATR mAb VH (aa) YAQKYQGRVTMTRDTSISTAYMQLSRLRPDD TAVYYCARDRPSHEWAMYFFDNWGQGTLV TVSS SARS-CoV-2  43 QVQLVQSGAEVKKPGASVKVSCKASGYTFT S300-v3.6 DYYIHWVRQAPGQGPEWLGYVLGYSGATR mAb VH (aa) YAQKYQGRVTMTRDTSISTAYMQLSRLRPDD TAVYYCARDRPSHEWAMYFFDNWGQGTLV TVSS SARS-CoV-2  44 QVQLVQSGAEVKKPGASVKVSCKASGYTFT S300-v3.7 DYYIHWVRQAPGQGPEWLGYVTGYSGATR mAb VH (aa) YAQKYQGRVTMTRDTSISTAYMQLSRLRPDD TAVYYCARDRPSHEWAMYFFDNWGQGTLV TVSS SARS-CoV-2  45 QVQLVQSGAEVKKPGASVKVSCKASGYTFT S300-v3.8 DYYIHWVRQAPGQGPEWLGYVNGYSGATR mAb VH (aa) YAQKYQGRVTMTRDTSISTAYMQLSRLRPDD TAVYYCARDRPSHEFAMYFFDNWGQGTLV TVSS SARS-CoV-2  46 QVQLVQSGAEVKKPGASVKVSCKASGYTFT S300-v3.9 DYYIHWVRQAPGQGPEWLGYVNGYSGATR mAb VH (aa) YAQKYQGRVTMTRDTSISTAYMQLSRLRPDD TAVYYCARDRPSHEYAMYFFDNWGQGTLV TVSS SARS-CoV-2  47 QIVLTQSPGTLSLSPGERATLSCRASQSVPSSY S300-v10 LAWYQQKPGQAPRLLIYGASGRATGIPDRFS mAb VL (Vκ) GSGSGTDFTLTIRRLEPEDFAVYYCQQYGSSP (aa) PLTFGGGTKVEIK SARS-CoV-2  48 QIVLTQSPGTLSLSPGERATLSCRASQSVPSSS S300-v11 LAWYQQKPGQAPRLLIYGASGRATGIPDRFS mAb VL (Vκ) GSGSGTDFTLTIRRLEPEDFAVYYCQQYGSSP (aa) PLTFGGGTKVEIK SARS-CoV-2  49 QIVLTQSPGTLSLSPGERATLSCRASQSVPSST S300-v12 LAWYQQKPGQAPRLLIYGASGRATGIPDRFS mAb VL (Vκ) GSGSGTDFTLTIRRLEPEDFAVYYCQQYGSSP (aa) PLTFGGGTKVEIK SARS-CoV-2  50 QIVLTQSPGTLSLSPGERATLSCRASQSVPSSA S300-v13 LAWYQQKPGQAPRLLIYGASGRATGIPDRFS mAb VL (Vκ) GSGSGTDFTLTIRRLEPEDFAVYYCQQYGSSP (aa) PLTFGGGTKVEIK SARS-CoV-2  51 QSVPSSY S300-v10 mAb CDRL1 (aa) SARS-CoV-2  51 QSVPSSS S300-v11 mAb CDRL1 (aa) SARS-CoV-2  53 QSVPSST S300-v12 mAb CDRL1 (aa) SARS-CoV-2  54 QSVPSSA S300-v13 mAb CDRL1 (aa) SARS-CoV-2  55 QVQLVESGGGVVQPGRSLRLSCAASGFTFSS S302 mAb YGMHWVRQAPGKGLEWVAVISYDGSNKYY VH (aa) ADSVKGRFTISRDNSKNTLYLQMNSLRAEDT AVYYCAKDISSGWDRVFDYWGQGTLVTVSS SARS-CoV-2  56 GFTFSSYG S302 mAb CDRH1 (aa) SARS-CoV-2  57 ISYDGSNK S302 mAb CDRH2 (aa) SARS-CoV-2  58 AKDISSGWDRVFDY S302 mAb CDRH3 (aa) SARS-CoV-2  59 EILLTQSPGTLSLSPGERATLSCRTSQSVGSSY S302 mAb LAWYQQKPGQAPRLLIYAASSRAIGIPDRFSG VL (Vκ) (aa) SGSGTDFTLTISRLEPEDFAVYYCQQYGSSPW TFGQGTKVEIK SARS-CoV-2  60 QSVGSSY S302 mAb CDRL1 (aa) SARS-CoV-2  61 AAS S302 mAb CDRL2 (aa) SARS-CoV-2  62 QQYGSSPWT S302 mAb CDRL3 (aa) SARS-CoV-2  63 EVQLVESGGGLVKPGGSLRLSCAASGFTFLT S303-v1 mAb YSMNWVRQTPGKRLQWVSAISGSGGATYY VH (aa) ADSVKGRFTISRDNSKNTLYLQMNTVTADDT AIYFCARERDDIFPMGLNAFDIWGQGAMVI VSS SARS-CoV-2  64 GFTFLTYS S303-v1 mAb CDRH1 (aa) SARS-CoV-2  65 ISGSGGAT S303-v1 mAb CDRH2 (aa) SARS-CoV-2  66 ARERDDIFPMGLNAFDI S303-v1 mAb CDRH3 (aa) SARS-CoV-2  67 DIQMTQSPSTLSASVGDRVTITCRASQSISNW S303-v1 mAb LAWYQQKPGKAPKLLIYKASSLESGVPSRFS VL (Vκ) (aa) GSGSGTEFTLTISSLQPDDSATYYCQQYDTYS WTFGQGTKVEIK SARS-CoV-2  68 QSISNW S303-v1 mAb CDRL1 (aa) SARS-CoV-2  69 KAS S303-v1 mAb CDRL2 (aa) SARS-CoV-2  70 QQYDTYSWT S303-v1 mAb CDRL3 (aa) SARS-CoV-2  71 DIQMTQSPSTLSASVGDRVTITCRASQSISNFL S303-v2 mAb AWYQQKPGKAPKLLIYKASSLESGVPSRFSGS VL (Vκ) (aa) GSGTEFTLTISSLQPDDSATYYCQQYDTYSW TFGQGTKVEIK SARS-CoV-2  72 DIQMTQSPSTLSASVGDRVTITCRASQSISNYL S303-v3 mAb AWYQQKPGKAPKLLIYKASSLESGVPSRFSGS VL (Vκ) (aa) GSGTEFTLTISSLQPDDSATYYCQQYDTYSW TFGQGTKVEIK SARS-CoV-2  73 QSISNF S303-v2 mAb CDRL1 (aa) SARS-CoV-2  74 QSISNY S303-v3 mAb CDRL1 (aa) SARS-CoV-2  75 DIQMTQSPSTLSASVGDRVTITCRASQSISNW S303-v4 mAb LAWYQQKPGKAPKLLIYKASSLESGVPSRFS VL (Vκ) (aa) GSGSGTEFTLTISSLQPDDSATYYCQQYDTYS FTFGQGTKVEIK SARS-CoV-2  76 DIQMTQSPSTLSASVGDRVTITCRASQSISNW S303-v5 mAb LAWYQQKPGKAPKLLIYKASSLESGVPSRFS VL (Vκ) (aa) GSGSGTEFTLTISSLQPDDSATYYCQQYDTYS YTFGQGTKVEIK SARS-CoV-2  77 QQYDTYSFT S303-v4 mAb CDRL3 (aa) SARS-CoV-2  78 QQYDTYSYT S303-v5 mAb CDRL3 (aa) SARS-CoV-2  79 EVQLVESGGGLVQPGGSLRLSCAASGFTFSS S304 mAb YDMHWVRQTTGKGLEWVSTIGTAGDTYYP VH (aa) DSVKGRFTISREDAKNSLYLQMNSLRAGDTA VYYCARGDSSGYYYYFDYWGQGTLLTVSS SARS-CoV-2  80 GFTFSSYD S304 mAb CDRH1 (aa) SARS-CoV-2  81 IGTAGDT S304 mAb CDRH2 (aa) SARS-CoV-2  82 ARGDSSGYYYYFDY S304 mAb CDRH3 (aa) SARS-CoV-2  83 DIQMTQSPSSLSAAVGDRVTITCRASQSIGSY S304 mAb LNWYQQKPGKAPKLLIYAASSLQSGVPSRFS VL (Vκ) (aa) GSGSGTDFTLTISSLQPEDFAIYYCQQSYVSPT YTFGPGTKVDIK SARS-CoV-2  84 QSIGSY S304 mAb CDRL1 (aa) SARS-CoV-2  85 AAS S304 mAb CDRL2 (aa) SARS-CoV-2  86 QQSYVSPTYT S304 mAb CDRL3 (aa) SARS-CoV-2  87 QVQLVQSGAEVKKPGASVKVSCKASTYTFTS S306 mAb FGISWVRQAPGQGLEWMGWITTYSGDTNYA VH (aa) QKFQGRVTMTTDTSTNTAYMELRSLRSDDTA VYYCASDYFDSSGYYHSFDYWGQGTLVTVS S SARS-CoV-2  88 TYTFTSFG S306 mAb CDRH1 (aa) SARS-CoV-2  89 ITTYSGDT S306 mAb CDRH2 (aa) SARS-CoV-2  90 ASDYFDSSGYYHSFDY S306 mAb CDRH3 (aa) SARS-CoV-2  91 EIVLTQSPDTLSLSPGERATLSCRASQSVSSYL S306 mAb AWYQQRPGQAPRLLIYDASKRATGIPARFSGS VL (Vκ) (aa) GSGTDFTLTISSLEPEDFAVYYCQQRSNWPP GCSFGQGTKVEIK SARS-CoV-2  92 QSVSSY S306 mAb CDRL1 (aa) SARS-CoV-2  93 DAS S306 mAb CDRL2 (aa) SARS-CoV-2  94 QQRSNWPPGCS S306 mAb CDRL3 (aa) SARS-CoV-2  95 QVQLVESGGGVVQPGRSLRLSCAASRFTFSS S308-v1 mAb YGMHWVRQAPGKGLEWVAVIWHDGNNKH VH (aa) YGDSVKGRVTISRDNSKNTLYLQMTSLRAED TAVVVCARAVTTFKGSGRAR1VIRGMDVWG QGTTVTVSS SARS-CoV-2  96 RFTFSSYG S308-v1 mAb CDRH1 (aa) SARS-CoV-2  97 IWHDGNNK S308-v1 mAb CDRH2 (aa) SARS-CoV-2  98 ARAVTTFKGSGRARMRGMDV S308-v1 mAb CDRH3 (aa) SARS-CoV-2  99 DIQLTQSPSFLSASVGDRVTITCRASQGINTYL S308-v1 mAb AWYQQKPGKAPKLLIYAASTLQSGVPSRFSG VL (Vκ) (aa) SGSGTEFTLTISSLQPEDFATYYCQHLDTYPF TFGPGTKVDIK SARS-CoV-2 100 QGINTY S308-v1 mAb CDRL1 (aa) SARS-CoV-2 101 AAS S308-v1 mAb CDRL2 (aa) SARS-CoV-2 102 QHLDTYPFT S308-v1 mAb CDRL3 (aa) SARS-CoV-2 103 QVQLVESGGGVVQPGRSLRLSCAASRFTFSS S308-v2 mAb YGMHWVRQAPGKGLEWVAVIWHDGNNKH VH (aa) YGDSVKGRVTISRDNSKNTLYLQMTSLRAED TAVYYCARAVTTFKGSGRARLRGMDVWG QGTTVTVSS SARS-CoV-2 104 ARAVTTFKGSGRARLRGMDV S308-v2 mAb CDRH3 (aa) SARS-CoV-2 105 QVQLVQSGAEVKKPGASVKVSCKASGYPFT S309-v1 mAb SYGISWVRQAPGQGLEWMGWISTYNGNTNY VH (aa) AQKFQGRVTMTTDTSTTTGYMELRRLRSDDT AVYYCARDYTRGAWFGESLIGGFDNWGQG TLVTVSS SARS-CoV-2 106 GYPFTSYG S309-v1 mAb CDRH1 (aa) SARS-CoV-2 107 ISTYNGNT S309-v1 mAb CDRH2 (aa) SARS-CoV-2 108 ARDYTRGAWFGESLIGGFDN S309-v1 mAb CDRH3 (aa) SARS-CoV-2 109 DIQMTQSPSSLSTSVGDRVTITCRASQGINNY S309-v1 mAb VAWYQQKPGKVPKLLIYGASTLQSGVPSRFR VL (Vκ) (aa)  GSGSGTGFTLTISSLQPEDVASYYCRKYNSAP (non- WTFGQGTRVEIK productive) SARS-CoV-2 110 QGINNY S309-v1 mAb CDRL1 (aa) (non- productive) SARS-CoV-2 111 GAS S309-v1 mAb CDRL2 (aa) (non- productive) SARS-CoV-2 112 RKYNSAPWT S309-v1 mAb CDRL3 (aa) (non- productive) SARS-CoV-2 113 QVQLVQSGAEVKKPGASVKVSCKASGYPFT S309-v1.1 SYGISWVRQAPGQGLEWMGWISTYQGNTN mAb VH (aa) YAQKFQGRVTMTTDTSTTTGYMELRRLRSD DTAVYYCARDYTRGAWFGESLIGGFDNWG QGTLVTVSS SARS-CoV-2 114 QVQLVQSGAEVKKPGASVKVSCKASGYPFT S309-v1.2 SYGISWVRQAPGQGLEWMGWISTYNSNTNY mAb VH (aa) AQKFQGRVTMTTDTSTTTGYMELRRLRSDDT AVYYCARDYTRGAWFGESLIGGFDNWGQG TLVTVSS SARS-CoV-2 115 QVQLVQSGAEVKKPGASVKVSCKASGYPFT S309-v1.3 SYGISWVRQAPGQGLEWMGWISTYNANTNY mAb VH (aa) AQKFQGRVTMTTDTSTTTGYMELRRLRSDDT AVYYCARDYTRGAWFGESLIGGFDNWGQG TLVTVSS SARS-CoV-2 116 QVQLVQSGAEVKKPGASVKVSCKASGYPFT S309-v1.4 SYGISWVRQAPGQGLEWMGWISTYNQNTNY mAb VH (aa) AQKFQGRVTMTTDTSTTTGYMELRRLRSDDT AVYYCARDYTRGAWFGESLIGGFDNWGQG TLVTVSS SARS-CoV-2 117 QVQLVQSGAEVKKPGASVKVSCKASGYPFT S309-v1.5 SYGISWVRQAPGQGLEWMGWISTYLGNTNY mAb VH (aa) AQKFQGRVTMTTDTSTTTGYMELRRLRSDDT AVYYCARDYTRGAWFGESLIGGFDNWGQG TLVTVSS SARS-CoV-2 118 QVQLVQSGAEVKKPGASVKVSCKASGYPFT S309-v1.6 SYGISWVRQAPGQGLEWMGWISTYTGNTNY mAb VH (aa) AQKFQGRVTMTTDTSTTTGYMELRRLRSDDT AVYYCARDYTRGAWFGESLIGGFDNWGQG TLVTVSS SARS-CoV-2 119 QVQLVQSGAEVKKPGASVKVSCKASGYPFT S309-v1.7 SYGISWVRQAPGQGLEWMGWISTYNGNTNY mAb VH (aa) AQKFQGRVTMTTDTSTTTGYMELRRLRSDDT AVYYCARDYTRGAFFGESLIGGFDNWGQG TLVTVSS SARS-CoV-2 120 QVQLVQSGAEVKKPGASVKVSCKASGYPFT S309-v1.8 SYGISWVRQAPGQGLEWMGWISTYNGNTNY mAb VH (aa) AQKFQGRVTMTTDTSTTTGYMELRRLRSDDT AVYYCARDYTRGAYFGESLIGGFDNWGQG TLVTVSS SARS-CoV-2 121 ISTYQGNT S309-v1.1 mAb CDRH2 (aa) SARS-CoV-2 122 ISTYNSNT S309-v1.2 mAb CDRH2 (aa) SARS-CoV-2 123 ISTYNANT S309-v1.3 mAb CDRH2 (aa) SARS-CoV-2 124 ISTYNQNT S309-v1.4 mAb CDRH2 (aa) SARS-CoV-2 125 ISTYLGNT S309-v1.5 mAb CDRH2 (aa) SARS-CoV-2 126 ISTYTGNT S309-v1.6 mAb CDRH2 (aa) SARS-CoV-2 127 ARDYTRGAFFGESLIGGFDN S309-v1.7 mAb CDRH3 (aa) SARS-CoV-2 128 ARDYTRGAYFGESLIGGFDN S309-v1.8 mAb CDRH3 (aa) SARS-CoV-2 129 QVQLVQSGAEVKKPGASVKVSCKASGYPFT S309-v2 mAb SYGISWVRQAPGQGLEWMGFISTYNGNTNY VH (aa) AQKFQGRVTMTTDTSTTTGYMELRRLRSDDT AVYYCARDYTRGAWFGESLIGGFDNWGQG TLVTVSS SARS-CoV-2 130 QVQLVQSGAEVKKPGASVKVSCKASGYPFT S309-v2.1 SYGISWVRQAPGQGLEWMGFISTYQGNTNY mAb VH (aa) AQKFQGRVTMTTDTSTTTGYMELRRLRSDDT AVYYCARDYTRGAWFGESLIGGFDNWGQG TLVTVSS SARS-CoV-2 131 QVQLVQSGAEVKKPGASVKVSCKASGYPFT S309-v2.2 SYGISWVRQAPGQGLEWMGFISTYNSNTNY mAb VH (aa) AQKFQGRVTMTTDTSTTTGYMELRRLRSDDT AVYYCARDYTRGAWFGESLIGGFDNWGQG TLVTVSS SARS-CoV-2 132 QVQLVQSGAEVKKPGASVKVSCKASGYPFT S309-v2.3 SYGISWVRQAPGQGLEWMGFISTYNANTNY mAb VH (aa) AQKFQGRVTMTTDTSTTTGYMELRRLRSDDT AVYYCARDYTRGAWFGESLIGGFDNWGQG TLVTVSS SARS-CoV-2 133 QVQLVQSGAEVKKPGASVKVSCKASGYPFT S309-v2.4 SYGISWVRQAPGQGLEWMGFISTYNQNTNY mAb VH (aa) AQKFQGRVTMTTDTSTTTGYMELRRLRSDDT AVYYCARDYTRGAWFGESLIGGFDNWGQG TLVTVSS SARS-CoV-2 134 QVQLVQSGAEVKKPGASVKVSCKASGYPFT S309-v2.5 SYGISWVRQAPGQGLEWMGFISTYLGNTNY mAb VH (aa) AQKFQGRVTMTTDTSTTTGYMELRRLRSDDT AVYYCARDYTRGAWFGESLIGGFDNWGQG TLVTVSS SARS-CoV-2 135 QVQLVQSGAEVKKPGASVKVSCKASGYPFT S309-v2.6 SYGISWVRQAPGQGLEWMGFISTYTGNTNY mAb VH (aa) AQKFQGRVTMTTDTSTTTGYMELRRLRSDDT AVYYCARDYTRGAWFGESLIGGFDNWGQG TLVTVSS SARS-CoV-2 136 QVQLVQSGAEVKKPGASVKVSCKASGYPFT S309-v2.7 SYGISWVRQAPGQGLEWMGFISTYNGNTNY mAb VH (aa) AQKFQGRVTMTTDTSTTTGYMELRRLRSDDT AVYYCARDYTRGAFFGESLIGGFDNWGQG TLVTVSS SARS-CoV-2 137 QVQLVQSGAEVKKPGASVKVSCKASGYPFT S309-v2.8 SYGISWVRQAPGQGLEWMGFISTYNGNTNY mAb VH (aa) AQKFQGRVTMTTDTSTTTGYMELRRLRSDDT AVYYCARDYTRGAYFGESLIGGFDNWGQG TLVTVSS SARS-CoV-2 138 QVQLVQSGAEVKKPGASVKVSCKASGYPFT S309-v3 mAb SYGISWVRQAPGQGLEWMGYISTYNGNTNY VH (aa) AQKFQGRVTMTTDTSTTTGYMELRRLRSDDT AVYYCARDYTRGAWFGESLIGGFDNWGQG TLVTVSS SARS-CoV-2 139 QVQLVQSGAEVKKPGASVKVSCKASGYPFT S309-v3.1 SYGISWVRQAPGQGLEWMGYISTYQGNTNY mAb VH (aa) AQKFQGRVTMTTDTSTTTGYMELRRLRSDDT AVYYCARDYTRGAWFGESLIGGFDNWGQG TLVTVSS SARS-CoV-2 140 QVQLVQSGAEVKKPGASVKVSCKASGYPFT S309-v3.2 SYGISWVRQAPGQGLEWMGYISTYNSNTNY mAb VH (aa) AQKFQGRVTMTTDTSTTTGYMELRRLRSDDT AVYYCARDYTRGAWFGESLIGGFDNWGQG TLVTVSS SARS-CoV-2 141 QVQLVQSGAEVKKPGASVKVSCKASGYPFT S309-v3.3 SYGISWVRQAPGQGLEWMGYISTYNANTNY mAb VH (aa) AQKFQGRVTMTTDTSTTTGYMELRRLRSDDT AVYYCARDYTRGAWFGESLIGGFDNWGQG TLVTVSS SARS-CoV-2 142 QVQLVQSGAEVKKPGASVKVSCKASGYPFT S309-v3.4 SYGISWVRQAPGQGLEWMGYISTYNQNTNY mAb VH (aa) AQKFQGRVTMTTDTSTTTGYMELRRLRSDDT AVYYCARDYTRGAWFGESLIGGFDNWGQG TLVTVSS SARS-CoV-2 143 QVQLVQSGAEVKKPGASVKVSCKASGYPFT S309-v3.5 SYGISWVRQAPGQGLEWMGYISTYLGNTNY mAb VH (aa) AQKFQGRVTMTTDTSTTTGYMELRRLRSDDT AVYYCARDYTRGAWFGESLIGGFDNWGQG TLVTVSS SARS-CoV-2 144 QVQLVQSGAEVKKPGASVKVSCKASGYPFT S309-v3.6 SYGISWVRQAPGQGLEWMGYISTYTGNTNY mAb VH (aa) AQKFQGRVTMTTDTSTTTGYMELRRLRSDDT AVYYCARDYTRGAWFGESLIGGFDNWGQG TLVTVSS SARS-CoV-2 145 QVQLVQSGAEVKKPGASVKVSCKASGYPFT S309-v3.7 SYGISWVRQAPGQGLEWMGYISTYNGNTNY mAb VH (aa) AQKFQGRVTMTTDTSTTTGYMELRRLRSDDT AVYYCARDYTRGAFFGESLIGGFDNWGQG TLVTVSS SARS-CoV-2 146 QVQLVQSGAEVKKPGASVKVSCKASGYPFT S309-v3.8 SYGISWVRQAPGQGLEWMGYISTYNGNTNY mAb VH (aa) AQKFQGRVTMTTDTSTTTGYMELRRLRSDDT AVYYCARDYTRGAYFGESLIGGFDNWGQG TLVTVSS SARS-CoV-2 147 DIQMTQSPSSLSTSVGDRVTITCRASQGINNY S309-v9 mAb VAWYQQKPGKVPKLLIYGASTLQSGVPSRFR VL (Vκ) (aa) GSGSGTGFTLTISSLQPEDVASYYCRKYNSAP (non- GTFGQGTRVEIK productive) SARS-CoV-2 148 DIQMTQSPSSLSTSVGDRVTITCRASQGINNY S309-v10 VAWYQQKPGKVPKLLIYGASTLQSGVPSRFR mAb VL GSGSGTGFTLTISSLQPEDVASYYCRKYNSAP (VK) (aa) RTFGQGTRVEIK (non- productive) SARS-CoV-2 149 DIQMTQSPSSLSTSVGDRVTITCRASQGINNY S309-v11 VAWYQQKPGKVPKLLIYGASTLQSGVPSRFR mAb VL (Vκ) GSGSGTGFTLTISSLQPEDVASYYCRKYNSAP (aa) FTFGQGTRVEIK (non- productive) SARS-CoV-2 150 DIQMTQSPSSLSTSVGDRVTITCRASQGINNY S309-v12 VAWYQQKPGKVPKLLIYGASTLQSGVPSRFR mAb VL (Vκ) GSGSGTGFTLTISSLQPEDVASYYCRKYNSAP (aa) YTFGQGTRVEIK (non- productive) SARS-CoV-2 151 RKYNSAPGT S309-v9 mAb CDRL3 (aa) (non- productive) SARS-CoV-2 152 RKYNSAPRT S309-v10 mAb CDRL3 (aa) (non- productive) SARS-CoV-2 153 RKYNSAPFT S309-v11 mAb CDRL3 (aa) (non- productive) SARS-CoV-2 154 RKYNSAPYT S309-v12 mAb CDRL3 (aa) (non- productive) SARS-CoV-2 155 QVQLVQSGAELKKPGSSVKVSCKASGGTFNS S310 mAb YSFNWVRQAPGQGLEWLGGIIPVLGTSNYA VH (aa) QKFQGRVAVTADEFTTTAYMELSSLRSEDTA VYYCATRTYDSSGYRPYYYGLDVWGQGTP VTVSS SARS-CoV-2 156 GGTFNSYS S310 mAb CDRH1 (aa) SARS-CoV-2 157 IIPVLGTS S310 mAb CDRH2 (aa) SARS-CoV-2 158 ATRTYDSSGYRPYYYGLDV S310 mAb CDRH3 (aa) SARS-CoV-2 159 QSALTQPASVSGSPGQSITISCTGTSSDVGSYN S310 mAb LVSWYQQRPGKAPELMIYEVTKRPSGLSNRF VL (Vκ) (aa) SGSKSGNTASLTISGLQAEDEADYYCCSYAG SDTVIFGGGTKVTVL SARS-CoV-2 160 SSDVGSYNL S310 mAb CDRL1 (aa) SARS-CoV-2 161 EVT S310 mAb CDRL2 (aa) SARS-CoV-2 162 CSYAGSDTVI S310 mAb CDRL3 (aa) Wuhan 163 1 attaaaggtt tataccttcc caggtaacaa accaaccaac seafood tttcgatctc ttgtagatct 61 gttctctaaa cgaactttaa market aatctgtgtg gctgtcactc ggctgcatgc ttagtgcact 121 pneumonia cacgcagtat aattaataac taattactgt cgttgacagg virus isolate acacgagtaa ctcgtctatc 181 ttctgcaggc tgcttacggt Wuhan-Hu-1 ttcgtccgtg ttgcagccga tcatcagcac atctaggttt 241 genomic cgtccgggtg tgaccgaaag gtaagatgga gagccttgtc sequence cctggtttca acgagaaaac 301 acacgtccaa ctcagtttgc (GenBank: ctgttttaca ggttcgcgac gtgctcgtac gtggctttgg 361 MN908947.3; agactccgtg gaggaggtct tatcagaggc cgtcaacat Jan. 23, cttaaagatg gcacttgtgg 421 cttagtagaa gttgaaaaag 2020) gcgttttgcc tcaacttgaa cagccctatg tgttcatcaa 481 acgttcggat gctcgaactg cacctcatgg tcatgttatg gttgagctgg tagcagaact 541 cgaaggcatt cagtacggtc gtagtggtga gacacttggt gtccttgtcc ctcatgtggg 601 cgaaatacca gtggcttacc gcaaggttct tcttcgtaag aacggtaata aaggagctgg 661 tggccatagt tacggcgccg atctaaagtc atttgactta ggcgacgagc ttggcactga 721 tccttatgaa gattttcaag aaaactggaa cactaaacat agcagtggtg ttacccgtga 781 actcatgcgt gagcttaacg gaggggcata cactcgctat gtcgataaca acttctgtgg 841 ccctgatggc taccctcttg agtgcattaa agaccttcta gcacgtgctg gtaaagcttc 901 atgcactttg tccgaacaac tggactttat tgacactaag aggggtgtat actgctgccg 961 tgaacatgag catgaaattg cttggtacac ggaacgttct gaaaagagct atgaattgca 1021 gacacctttt gaaattaaat tggcaaagaa atttgacacc ttcaatgggg aatgtccaaa 1081 ttttgtattt cccttaaatt ccataatcaa gactattcaa ccaagggttg aaaagaaaaa 1141 gcttgatggc tttatgggta gaattcgatc tgtctatcca gttgcgtcac caaatgaatg 1201 caaccaaatg tgcctttcaa ctctcatgaa gtgtgatcat tgtggtgaaa cttcatggca 1261 gacgggcgat tttgttaaag ccacttgcga attttgtggc actgagaatt tgactaaaga 1321 aggtgccact acttgtggtt acttacccca aaatgctgtt gttaaaattt attgtccagc 1381 atgtcacaat tcagaagtag gacctgagca tagtcttgcc gaataccata atgaatctgg 1441 cttgaaaacc attcttcgta agggtggtcg cactattgcc tttggaggct gtgtgttctc 1501 ttatgttggt tgccataaca agtgtgccta ttgggttcca cgtgctagcg ctaacatagg 1561 ttgtaaccat acaggtgttg ttggagaagg ttccgaaggt cttaatgaca accttcttga 1621 aatactccaa aaagagaaag tcaacatcaa tattgttggt gactttaaac ttaatgaaga 1681 gatcgccatt attttggcat ctttttctgc ttccacaagt gcttttgtgg aaactgtgaa 1741 aggtttggat tataaagcat tcaaacaaat tgttgaatcc tgtggtaatt ttaaagttac 1801 aaaaggaaaa gctaaaaaag gtgcctggaa tattggtgaa cagaaatcaa tactgagtcc 1861 tctttatgca tttgcatcag aggctgctcg tgttgtacga tcaattttct cccgcactct 1921 tgaaactgct caaaattctg tgcgtgtttt acagaaggcc gctataacaa tactagatgg 1981 aatttcacag tattcactga gactcattga tgctatgatg ttcacatctg atttggctac 2041 taacaatcta gttgtaatgg cctacattac aggtggtgtt gttcagttga cttcgcagtg 2101 gctaactaac atctttggca ctgtttatga aaaactcaaa cccgtccttg attggcttga 2161 agagaagttt aaggaaggtg tagagtttct tagagacggt tgggaaattg ttaaatttat 2221 ctcaacctgt gcttgtgaaa ttgtcggtgg acaaattgtc acctgtgcaa aggaaattaa 2281 ggagagtgtt cagacattct ttaagcttgt aaataaattt ttggctttgt gtgctgactc 2341 tatcattatt ggtggagcta aacttaaagc cttgaattta ggtgaaacat ttgtcacgca 2401 ctcaaaggga ttgtacagaa agtgtgttaa atccagagaa gaaactggcc tactcatgcc 2461 tctaaaagcc ccaaaagaaa ttatcttett agagggagaa acacttccca cagaagtgtt 2521 aacagaggaa gttgtcttga aaactggtga tttacaacca ttagaacaac ctactagtga 2581 agctgttgaa gctccattgg ttggtacacc agtttgtatt aacgggctta tgttgctcga 2641 aatcaaagac acagaaaagt actgtgccct tgcacctaat atgatggtaa caaacaatac 2701 cttcacactc aaaggcggtg caccaacaaa ggttactttt ggtgatgaca ctgtgataga 2761 agtgcaaggt tacaagagtg tgaatatcac ttttgaactt gatgaaagga ttgataaagt 2821 acttaatgag aagtgctctg cctatacagt tgaactcggt acagaagtaa atgagttcgc 2881 ctgtgttgtg gcagatgctg tcataaaaac tttgcaacca gtatctgaat tacttacacc 2941 actgggcatt gatttagatg agtggagtat ggctacatac tacttatttg atgagtctgg 3001 tgagtttaaa ttggcttcac atatgtattg ttctttctac cctccagatg aggatgaaga 3061 agaaggtgat tgtgaagaag aagagtttga gccatcaact caatatgagt atggtactga 3121 agatgattac caaggtaaac ctttggaatt tggtgccact tctgctgctc ttcaacctga 3181 agaagagcaa gaagaagatt ggttagatga tgatagtcaa caaactgttg gtcaacaaga 3241 cggcagtgag gacaatcaga caactactat tcaaacaatt gttgaggttc aacctcaatt 3301 agagatggaa cttacaccag ttgttcagac tattgaagtg aatagtttta gtggttattt 3361 aaaacttact gacaatgtat acattaaaaa tgcagacatt gtggaagaag ctaaaaaggt 3421 aaaaccaaca gtggttgtta atgcagccaa tgtttacctt aaacatggag gaggtgttgc 3481 aggagcctta aataaggcta ctaacaatgc catgcaagtt gaatctgatg attacatagc 3541 tactaatgga ccacttaaag tgggtggtag ttgtgtttta agcggacaca atcttgctaa 3601 acactgtctt catgttgtcg gcccaaatgt taacaaaggt gaagacattc aacttcttaa 3661 gagtgcttat gaaaatttta atcagcacga agttctactt gcaccattat tatcagctgg 3721 tatttttggt gctgacccta tacattcttt aagagtttgt gtagatactg ttcgcacaaa 3781 tgtctactta gctgtctttg ataaaaatct ctatgacaaa cttgtttcaa gctttttgga 3841 aatgaagagt gaaaagcaag ttgaacaaaa gatcgctgag attcctaaag aggaagttaa 3901 gccatttata actgaaagta aaccttcagt tgaacagaga aaacaagatg ataagaaaat 3961 caaagcttgt gttgaagaag ttacaacaac tctggaagaa actaagttcc tcacagaaaa 4021 cttgttactt tatattgaca ttaatggcaa tcttcatcca gattctgcca ctcttgttag 4081 tgacattgac atcactttct taaagaaaga tgctccatat atagtgggtg atgttgttca 4141 agagggtgtt ttaactgctg tggttatacc tactaaaaag gctggtggca ctactgaaat 4201 gctagcgaaa gctttgagaa aagtgccaac agacaattat ataaccactt acccgggtca 4261 gggtttaaat ggttacactg tagaggaggc aaagacagtg cttaaaaagt gtaaaagtgc 4321 cttttacatt ctaccatcta ttatctctaa tgagaagcaa gaaattcttg gaactgtttc 4381 ttggaatttg cgagaaatgc ttgcacatgc agaagaaaca cgcaaattaa tgcctgtctg 4441 tgtggaaact aaagccatag tttcaactat acagcgtaaa tataagggta ttaaaataca 4501 agagggtgtg gttgattatg gtgctagatt ttacttttac accagtaaaa caactgtagc 4561 gtcacttatc aacacactta acgatctaaa tgaaactctt gttacaatgc cacttggcta 4621 tgtaacacat ggcttaaatt tggaagaagc tgctcggtat atgagatctc tcaaagtgcc 4681 agctacagtt tctgtttctt cacctgatgc tgttacagcg tataatggtt atcttacttc 4741 ttcttctaaa acacctgaag aacattttat tgaaaccatc tcacttgctg gttcctataa 4801 agattggtcc tattctggac aatctacaca actaggtata gaatttctta agagaggtga 4861 taaaagtgta tattacacta gtaatcctac cacattccac ctagatggtg aagttatcac 4921 ctttgacaat cttaagacac ttctttcttt gagagaagtg aggactatta aggtgtttac 4981 aacagtagac aacattaacc tccacacgca agttgtggac atgtcaatga catatggaca 5041 acagtttggt ccaacttatt tggatggagc tgatgttact aaaataaaac ctcataattc 5101 acatgaaggt aaaacatttt atgttttacc taatgatgac actctacgtg ttgaggcttt 5161 tgagtactac cacacaactg atcctagttt tctgggtagg tacatgtcag cattaaatca 5221 cactaaaaag tggaaatacc cacaagttaa tggtttaact tctattaaat gggcagataa 5281 caactgttat cttgccactg cattgttaac actccaacaa atagagttga agtttaatcc 5341 acctgctcta caagatgctt attacagagc aagggctggt gaagctgcta acttttgtgc 5401 acttatctta gcctactgta ataagacagt aggtgagtta ggtgatgtta gagaaacaat 5461 gagttacttg tttcaacatg ccaatttaga ttcttgcaaa agagtcttga acgtggtgtg 5521 taaaacttgt ggacaacagc agacaaccct taagggtgta gaagctgtta tgtacatggg 5581 cacactttct tatgaacaat ttaagaaagg tgttcagata ccttgtacgt gtggtaaaca 5641 agctacaaaa tatctagtac aacaggagtc accttttgtt atgatgtcag caccacctgc 5701 tcagtatgaa cttaagcatg gtacatttac ttgtgctagt gagtacactg gtaattacca 5761 gtgtggtcac tataaacata taacttctaa agaaactttg tattgcatag acggtgcttt 5821 acttacaaag tcctcagaat acaaaggtcc tattacggat gttttctaca aagaaaacag 5881 ttacacaaca accataaaac cagttactta taaattggat ggtgttgttt gtacagaaat 5941 tgaccctaag ttggacaatt attataagaa agacaattct tatttcacag agcaaccaat 6001 tgatcttgta ccaaaccaac catatccaaa cgcaagcttc gataatttta agtttgtatg 6061 tgataatatc aaatttgctg atgatttaaa ccagttaact ggttataaga aacctgcttc 6121 aagagagctt aaagttacat ttttccctga cttaaatggt gatgtggtgg ctattgatta 6181 taaacactac acaccctctt ttaagaaagg agctaaattg ttacataaac ctattgtttg 6241 gcatgttaac aatgcaacta ataaagccac gtataaacca aatacctggt gtatacgttg 6301 tctttggagc acaaaaccag ttgaaacatc aaattcgttt gatgtactga agtcagagga 6361 cgcgcaggga atggataatc ttgcctgcga agatctaaaa ccagtctctg aagaagtagt 6421 ggaaaatcct accatacaga aagacgttct tgagtgtaat gtgaaaacta ccgaagttgt 6481 aggagacatt atacttaaac cagcaaataa tagtttaaaa attacagaag aggttggcca 6541 cacagatcta atggctgctt atgtagacaa ttctagtctt actattaaga aacctaatga 6601 attatctaga gtattaggtt tgaaaaccct tgctactcat ggtttagctg ctgttaatag 6661 tgtcccttgg gatactatag ctaattatgc taagcctttt cttaacaaag ttgttagtac 6721 aactactaac atagttacac ggtgtttaaa ccgtgtttgt actaattata tgccttattt 6781 ctttacttta ttgctacaat tgtgtacttt tactagaagt acaaattcta gaattaaagc 6841 atctatgccg actactatag caaagaatac tgttaagagt gtcggtaaat tttgtctaga 6901 ggcttcattt aattatttga agtcacctaa tttttctaaa ctgataaata ttataatttg 6961 gtttttacta ttaagtgttt gcctaggttc tttaatctac tcaaccgctg ctttaggtgt 7021 tttaatgtct aatttaggca tgccttctta ctgtactggt tacagagaag gctatttgaa 7081 ctctactaat gtcactattg caacctactg tactggttct ataccttgta gtgtttgtct 7141 tagtggttta gattctttag acacctatcc ttctttagaa actatacaaa ttaccatttc 7201 atcttttaaa tgggatttaa ctgcttttgg cttagttgca gagtggtttt tggcatatat 7261 tcttttcact aggtttttct atgtacttgg attggctgca atcatgcaat tgtttttcag 7321 ctattttgca gtacatttta ttagtaattc ttggcttatg tggttaataa ttaatcttgt 7381 acaaatggcc ccgatttcag ctatggttag aatgtacatc ttctttgcat cattttatta 7441 tgtatggaaa agttatgtgc atgttgtaga cggttgtaat tcatcaactt gtatgatgtg 7501 ttacaaacgt aatagagcaa caagagtcga atgtacaact attgttaatg gtgttagaag 7561 gtccttttat gtctatgcta atggaggtaa aggcttttgc aaactacaca attggaattg 7621 tgttaattgt gatacattct gtgctggtag tacatttatt agtgatgaag ttgcgagaga 7681 cttgtcacta cagtttaaaa gaccaataaa tcctactgac cagtcttctt acatcgttga 7741 tagtgttaca gtgaagaatg gttccatcca tctttacttt gataaagctg gtcaaaagac 7801 ttatgaaaga cattctctct ctcattttgt taacttagac aacctgagag ctaataacac 7861 taaaggttca ttgcctatta atgttatagt ttttgatggt aaatcaaaat gtgaagaatc 7921 atctgcaaaa tcagcgtctg tttactacag tcagcttatg tgtcaaccta tactgttact 7981 agatcaggca ttagtgtctg atgttggtga tagtgcggaa gttgcagtta aaatgtttga 8041 tgcttacgtt aatacgtttt catcaacttt taacgtacca atggaaaaac tcaaaacact 8101 agttgcaact gcagaagctg aacttgcaaa gaatgtgtcc ttagacaatg tcttatctac 8161 ttttatttca gcagctcggc aagggtttgt tgattcagat gtagaaacta aagatgttgt 8221 tgaatgtctt aaattgtcac atcaatctga catagaagtt actggcgata gttgtaataa 8281 ctatatgctc acctataaca aagttgaaaa catgacaccc cgtgaccttg gtgcttgtat 8341 tgactgtagt gcgcgtcata ttaatgcgca ggtagcaaaa agtcacaaca ttgctttgat 8401 atggaacgtt aaagatttca tgtcattgtc tgaacaacta cgaaaacaaa tacgtagtgc 8461 tgctaaaaag aataacttac cttttaagtt gacatgtgca actactagac aagttgttaa 8521 tgttgtaaca acaaagatag cacttaaggg tggtaaaatt gttaataatt ggttgaagca 8581 gttaattaaa gttacacttg tgttcctttt tgttgctgct attttctatt taataacacc 8641 tgttcatgtc atgtctaaac atactgactt ttcaagtgaa atcataggat acaaggctat 8701 tgatggtggt gtcactcgtg acatagcatc tacagatact tgttttgcta acaaacatgc 8761 tgattttgac acatggttta gccagcgtgg tggtagttat actaatgaca aagcttgccc 8821 attgattgct gcagtcataa caagagaagt gggttttgtc gtgcctggtt tgcctggcac 8881 gatattacgc acaactaatg gtgacttttt gcatttctta cctagagttt ttagtgcagt 8941 tggtaacatc tgttacacac catcaaaact tatagagtac actgactttg caacatcagc 9001 ttgtgttttg gctgctgaat gtacaatttt taaagatgct tctggtaagc cagtaccata 9061 ttgttatgat accaatgtac tagaaggttc tgttgcttat gaaagtttac gccctgacac 9121 acgttatgtg ctcatggatg gctctattat tcaatttcct aacacctacc ttgaaggttc 9181 tgttagagtg gtaacaactt ttgattctga gtactgtagg cacggcactt gtgaaagatc 9241 agaagctggt gtttgtgtat ctactagtgg tagatgggta cttaacaatg attattacag 9301 atctttacca ggagttttct gtggtgtaga tgctgtaaat ttacttacta atatgtttac 9361 accactaatt caacctattg gtgctttgga catatcagca tctatagtag ctggtggtat 9421 tgtagctatc gtagtaacat gccttgccta ctattttatg aggtttagaa gagcttttgg 9481 tgaatacagt catgtagttg cctttaatac tttactattc cttatgtcat tcactgtact 9541 ctgtttaaca ccagtttact cattcttacc tggtgtttat tctgttattt acttgtactt 9601 gacattttat cttactaatg atgtttcttt tttagcacat attcagtgga tggttatgtt 9661 cacaccttta gtacctttct ggataacaat tgcttatatc atttgtattt ccacaaagca 9721 tttctattgg ttctttagta attacctaaa gagacgtgta gtctttaatg gtgtttcctt 9781 tagtactttt gaagaagctg cgctgtgcac ctttttgtta aataaagaaa tgtatctaaa 9841 gttgcgtagt gatgtgctat tacctcttac gcaatataat agatacttag ctctttataa 9901 taagtacaag tattttagtg gagcaatgga tacaactagc tacagagaag ctgcttgttg 9961 tcatctcgca aaggctctca atgacttcag taactcaggt tctgatgttc tttaccaacc 10021 accacaaacc tctatcacct cagctgtttt gcagagtggt tttagaaaaa tggcattccc 10081 atctggtaaa gttgagggtt gtatggtaca agtaacttgt ggtacaacta cacttaacgg 10141 tctttggctt gatgacgtag tttactgtcc aagacatgtg atctgcacct ctgaagacat 10201 gcttaaccct aattatgaag atttactcat tcgtaagtct aatcataatt tcttggtaca 10261 ggctggtaat gttcaactca gggttattgg acattctatg caaaattgtg tacttaagct 10321 taaggttgat acagccaatc ctaagacacc taagtataag tttgttcgca ttcaaccagg 10381 acagactttt tcagtgttag cttgttacaa tggttcacca tctggtgttt accaatgtgc 10441 tatgaggccc aatttcacta ttaagggttc attccttaat ggttcatgtg gtagtgttgg 10501 ttttaacata gattatgact gtgtctcttt ttgttacatg caccatatgg aattaccaac 10561 tggagttcat gctggcacag acttagaagg taacttttat ggaccttttg ttgacaggca 10621 aacagcacaa gcagctggta cggacacaac tattacagtt aatgttttag cttggttgta 10681 cgctgctgtt ataaatggag acaggtggtt tctcaatcga tttaccacaa ctcttaatga 10741 ctttaacctt gtggctatga agtacaatta tgaacctcta acacaagacc atgttgacat 10801 actaggacct ctttctgctc aaactggaat tgccgtttta gatatgtgtg cttcattaaa 10861 agaattactg caaaatggta tgaatggacg taccatattg ggtagtgctt tattagaaga 10921 tgaatttaca ccttttgatg ttgttagaca atgctcaggt gttactttcc aaagtgcagt 10981 gaaaagaaca atcaagggta cacaccactg gttgttactc acaattttga cttcactttt 11041 agttttagtc cagagtactc aatggtcttt gttctttttt ttgtatgaaa atgccttttt 11101 accttttgct atgggtatta ttgctatgtc tgcttttgca atgatgtttg tcaaacataa 11161 gcatgcattt ctctgtttgt ttttgttacc ttctcttgcc actgtagctt attttaatat 11221 ggtctatatg cctgctagtt gggtgatgcg tattatgaca tggttggata tggttgatac 11281 tagtttgtct ggttttaagc taaaagactg tgttatgtat gcatcagctg tagtgttact 11341 aatccttatg acagcaagaa ctgtgtatga tgatggtgct aggagagtgt ggacacttat 11401 gaatgtcttg acactcgttt ataaagttta ttatggtaat gctttagatc aagccatttc 11461 catgtgggct cttataatct ctgttacttc taactactca ggtgtagtta caactgtcat 11521 gtttttggcc agaggtattg tttttatgtg tgttgagtat tgccctattt tcttcataac 11581 tggtaataca cttcagtgta taatgctagt ttattgtttc ttaggctatt tttgtacttg 11641 ttactttggc ctcttttgtt tactcaaccg ctactttaga ctgactcttg gtgtttatga 11701 ttacttagtt tctacacagg agtttagata tatgaattca cagggactac tcccacccaa 11761 gaatagcata gatgccttca aactcaacat taaattgttg ggtgttggtg gcaaaccttg 11821 tatcaaagta gccactgtac agtctaaaat gtcagatgta aagtgcacat cagtagtctt 11881 actctcagtt ttgcaacaac tcagagtaga atcatcatct aaattgtggg ctcaatgtgt 11941 ccagttacac aatgacattc tcttagctaa agatactact gaagcctttg aaaaaatggt 12001 ttcactactt tctgttttgc tttccatgca gggtgctgta gacataaaca agctttgtga 12061 agaaatgctg gacaacaggg caaccttaca agctatagcc tcagagttta gttcccttcc 12121 atcatatgca gcttttgcta ctgctcaaga agcttatgag caggctgttg ctaatggtga 12181 ttctgaagtt gttcttaaaa agttgaagaa gtctttgaat gtggctaaat ctgaatttga 12241 ccgtgatgca gccatgcaac gtaagttgga aaagatggct gatcaagcta tgacccaaat 12301 gtataaacag gctagatctg aggacaagag ggcaaaagtt actagtgcta tgcagacaat 12361 gcttttcact atgcttagaa agttggataa tgatgcactc aacaacatta tcaacaatgc 12421 aagagatggt tgtgttccct tgaacataat acctcttaca acagcagcca aactaatggt 12481 tgtcatacca gactataaca catataaaaa tacgtgtgat ggtacaacat ttacttatgc 12541 atcagcattg tgggaaatcc aacaggttgt agatgcagat agtaaaattg ttcaacttag 12601 tgaaattagt atggacaatt cacctaattt agcatggcct cttattgtaa cagctttaag 12661 ggccaattct gctgtcaaat tacagaataa tgagcttagt cctgttgcac tacgacagat 12721 gtcttgtgct gccggtacta cacaaactgc ttgcactgat gacaatgcgt tagcttacta 12781 caacacaaca aagggaggta ggtttgtact tgcactgtta tccgatttac aggatttgaa 12841 atgggctaga ttccctaaga gtgatggaac tggtactatc tatacagaac tggaaccacc 12901 ttgtaggttt gttacagaca cacctaaagg tcctaaagtg aagtatttat actttattaa 12961 aggattaaac aacctaaata gaggtatggt acttggtagt ttagctgcca cagtacgtct 13021 acaagctggt aatgcaacag aagtgcctgc caattcaact gtattatctt tctgtgcttt 13081 tgctgtagat gctgctaaag cttacaaaga ttatctagct agtgggggac aaccaatcac 13141 taattgtgtt aagatgttgt gtacacacac tggtactggt caggcaataa cagttacacc 13201 ggaagccaat atggatcaag aatcctttgg tggtgcatcg tgttgtctgt actgccgttg 13261 ccacatagat catccaaatc ctaaaggatt ttgtgactta aaaggtaagt atgtacaaat 13321 acctacaact tgtgctaatg accctgtggg ttttacactt aaaaacacag tctgtaccgt 13381 ctgcggtatg tggaaaggtt atggctgtag ttgtgatcaa ctccgcgaac ccatgcttca 13441 gtcagctgat gcacaatcgt ttttaaacgg gtttgcggtg taagtgcagc ccgtcttaca 13501 ccgtgcggca caggcactag tactgatgtc gtatacaggg cttttgacat ctacaatgat 13561 aaagtagctg gttttgctaa attcctaaaa actaattgtt gtcgcttcca agaaaaggac 13621 gaagatgaca atttaattga ttcttacttt gtagttaaga gacacacttt ctctaactac 13681 caacatgaag aaacaattta taatttactt aaggattgtc cagctgttgc taaacatgac 13741 ttctttaagt ttagaataga cggtgacatg gtaccacata tatcacgtca acgtcttact 13801 aaatacacaa tggcagacct cgtctatgct ttaaggcatt ttgatgaagg taattgtgac 13861 acattaaaag aaatacttgt cacatacaat tgttgtgatg atgattattt caataaaaag 13921 gactggtatg attttgtaga aaacccagat atattacgcg tatacgccaa cttaggtgaa 13981 cgtgtacgcc aagctttgtt aaaaacagta caattctgtg atgccatgcg aaatgctggt 14041 attgttggtg tactgacatt agataatcaa gatctcaatg gtaactggta tgatttcggt 14101 gatttcatac aaaccacgcc aggtagtgga gttcctgttg tagattctta ttattcattg 14161 ttaatgccta tattaacctt gaccagggct ttaactgcag agtcacatgt tgacactgac 14221 ttaacaaagc cttacattaa gtgggatttg ttaaaatatg acttcacgga agagaggtta 14281 aaactctttg accgttattt taaatattgg gatcagacat accacccaaa ttgtgttaac 14341 tgtttggatg acagatgcat tctgcattgt gcaaacttta atgttttatt ctctacagtg 14401 ttcccaccta caagttttgg accactagtg agaaaaatat ttgttgatgg tgttccattt 14461 gtagtttcaa ctggatacca cttcagagag ctaggtgttg tacataatca ggatgtaaac 14521 ttacatagct ctagacttag ttttaaggaa ttacttgtgt atgctgctga ccctgctatg 14581 cacgctgctt ctggtaatct attactagat aaacgcacta cgtgcttttc agtagctgca 14641 cttactaaca atgttgcttt tcaaactgtc aaacccggta attttaacaa agacttctat 14701 gactttgctg tgtctaaggg tttctttaag gaaggaagtt ctgttgaatt aaaacacttc 14761 ttctttgctc aggatggtaa tgctgctatc agcgattatg actactatcg ttataatcta 14821 ccaacaatgt gtgatatcag acaactacta tttgtagttg aagttgttga taagtacttt 14881 gattgttacg atggtggctg tattaatgct aaccaagtca tcgtcaacaa cctagacaaa 14941 tcagctggtt ttccatttaa taaatggggt aaggctagac tttattatga ttcaatgagt 15001 tatgaggatc aagatgcact tttcgcatat acaaaacgta atgtcatccc tactataact 15061 caaatgaatc ttaagtatgc cattagtgca aagaatagag ctcgcaccgt agctggtgtc 15121 tctatctgta gtactatgac caatagacag tttcatcaaa aattattgaa atcaatagcc 15181 gccactagag gagctactgt agtaattgga acaagcaaat tctatggtgg ttggcacaac 15241 atgttaaaaa ctgtttatag tgatgtagaa aaccctcacc ttatgggttg ggattatcct 15301 aaatgtgata gagccatgcc taacatgctt agaattatgg cctcacttgt tcttgctcgc 15361 aaacatacaa cgtgttgtag cttgtcacac cgtttctata gattagctaa tgagtgtgct 15421 caagtattga gtgaaatggt catgtgtggc ggttcactat atgttaaacc aggtggaacc 15481 tcatcaggag atgccacaac tgcttatgct aatagtgttt ttaacatttg tcaagctgtc 15541 acggccaatg ttaatgcact tttatctact gatggtaaca aaattgccga taagtatgtc 15601 cgcaatttac aacacagact ttatgagtgt ctctatagaa atagagatgt tgacacagac 15661 tttgtgaatg agttttacgc atatttgcgt aaacatttct caatgatgat actctctgac 15721 gatgctgttg tgtgtttcaa tagcacttat gcatctcaag gtctagtggc tagcataaag 15781 aactttaagt cagttcttta ttatcaaaac aatgttttta tgtctgaagc aaaatgttgg 15841 actgagactg accttactaa aggacctcat gaattttgct ctcaacatac aatgctagtt 15901 aaacagggtg atgattatgt gtaccttcct tacccagatc catcaagaat cctaggggcc 15961 ggctgttttg tagatgatat cgtaaaaaca gatggtacac ttatgattga acggttcgtg 16021 tctttagcta tagatgctta cccacttact aaacatccta atcaggagta tgctgatgtc 16081 tttcatttgt acttacaata cataagaaag ctacatgatg agttaacagg acacatgtta 16141 gacatgtatt ctgttatgct tactaatgat aacacttcaa ggtattggga acctgagttt 16201 tatgaggcta tgtacacacc gcatacagtc ttacaggctg ttggggcttg tgttctttgc 16261 aattcacaga cttcattaag atgtggtgct tgcatacgta gaccattctt atgttgtaaa 16321 tgctgttacg accatgtcat atcaacatca cataaattag tcttgtctgt taatccgtat 16381 gtttgcaatg ctccaggttg tgatgtcaca gatgtgactc aactttactt aggaggtatg 16441 agctattatt gtaaatcaca taaaccaccc attagttttc cattgtgtgc taatggacaa 16501 gtttttggtt tatataaaaa tacatgtgtt ggtagcgata atgttactga ctttaatgca 16561 attgcaacat gtgactggac aaatgctggt gattacattt tagctaacac ctgtactgaa 16621 agactcaagc tttttgcagc agaaacgctc aaagctactg aggagacatt taaactgtct 16681 tatggtattg ctactgtacg tgaagtgctg tctgacagag aattacatct ttcatgggaa 16741 gttggtaaac ctagaccacc acttaaccga aattatgtct ttactggtta tcgtgtaact 16801 aaaaacagta aagtacaaat aggagagtac acctttgaaa aaggtgacta tggtgatgct 16861 gttgtttacc gaggtacaac aacttacaaa ttaaatgttg gtgattattt tgtgctgaca 16921 tcacatacag taatgccatt aagtgcacct acactagtgc cacaagagca ctatgttaga 16981 attactggct tatacccaac actcaatatc tcagatgagt tttctagcaa tgttgcaaat 17041 tatcaaaagg ttggtatgca aaagtattct acactccagg gaccacctgg tactggtaag 17101 agtcattttg ctattggcct agctctctac tacccttctg ctcgcatagt gtatacagct 17161 tgctctcatg ccgctgttga tgcactatgt gagaaggcat taaaatattt gcctatagat 17221 aaatgtagta gaattatacc tgcacgtgct cgtgtagagt gttttgataa attcaaagtg 17281 aattcaacat tagaacagta tgtcttttgt actgtaaatg cattgcctga gacgacagca 17341 gatatagttg tctttgatga aatttcaatg gccacaaatt atgatttgag tgttgtcaat 17401 gccagattac gtgctaagca ctatgtgtac attggcgacc ctgctcaatt acctgcacca 17461 cgcacattgc taactaaggg cacactagaa ccagaatatt tcaattcagt gtgtagactt 17521 atgaaaacta taggtccaga catgttcctc ggaacttgtc ggcgttgtcc tgctgaaatt 17581 gttgacactg tgagtgcttt ggtttatgat aataagctta aagcacataa agacaaatca 17641 gctcaatgct ttaaaatgtt ttataagggt gttatcacgc atgatgtttc atctgcaatt 17701 aacaggccac aaataggcgt ggtaagagaa ttccttacac gtaaccctgc ttggagaaaa 17761 gctgtcttta tttcacctta taattcacag aatgctgtag cctcaaagat tttgggacta 17821 ccaactcaaa ctgttgattc atcacagggc tcagaatatg actatgtcat attcactcaa 17881 accactgaaa cagctcactc ttgtaatgta aacagattta atgttgctat taccagagca 17941 aaagtaggca tactttgcat aatgtctgat agagaccttt atgacaagtt gcaatttaca 18001 agtcttgaaa ttccacgtag gaatgtggca actttacaag ctgaaaatgt aacaggactc 18061 tttaaagatt gtagtaaggt aatcactggg ttacatccta cacaggcacc tacacacctc 18121 agtgttgaca ctaaattcaa aactgaaggt ttatgtgttg acatacctgg catacctaag 18181 gacatgacct atagaagact catctctatg atgggtttta aaatgaatta tcaagttaat 18241 ggttacccta acatgtttat cacccgcgaa gaagctataa gacatgtacg tgcatggatt 18301 ggcttcgatg tcgaggggtg tcatgctact agagaagctg ttggtaccaa tttaccttta 18361 cagctaggtt tttctacagg tgttaaccta gttgctgtac ctacaggtta tgttgataca 18421 cctaataata cagatttttc cagagttagt gctaaaccac cgcctggaga tcaatttaaa 18481 cacctcatac cacttatgta caaaggactt ccttggaatg tagtgcgtat aaagattgta 18541 caaatgttaa gtgacacact taaaaatctc tctgacagag tcgtatttgt cttatgggca 18601 catggctttg agttgacatc tatgaagtat tttgtgaaaa taggacctga gcgcacctgt 18661 tgtctatgtg atagacgtgc cacatgcttt tccactgctt cagacactta tgcctgttgg 18721 catcattcta ttggatttga ttacgtctat aatccgttta tgattgatgt tcaacaatgg 18781 ggttttacag gtaacctaca aagcaaccat gatctgtatt gtcaagtcca tggtaatgca 18841 catgtagcta gttgtgatgc aatcatgact aggtgtctag ctgtccacga gtgctttgtt 18901 aagcgtgttg actggactat tgaatatcct ataattggtg atgaactgaa gattaatgcg 18961 gcttgtagaa aggttcaaca catggttgtt aaagctgcat tattagcaga caaattccca 19021 gttcttcacg acattggtaa ccctaaagct attaagtgtg tacctcaagc tgatgtagaa 19081 tggaagttct atgatgcaca gccttgtagt gacaaagctt ataaaataga agaattattc 19141 tattcttatg ccacacattc tgacaaattc acagatggtg tatgcctatt ttggaattgc 19201 aatgtcgata gatatcctgc taattccatt gtttgtagat ttgacactag agtgctatct 19261 aaccttaact tgcctggttg tgatggtggc agtttgtatg taaataaaca tgcattccac 19321 acaccagctt ttgataaaag tgctifigtt aatttaaaac aattaccatt tttctattac 19381 tctgacagtc catgtgagtc tcatggaaaa caagtagtgt cagatataga ttatgtacca 19441 ctaaagtctg ctacgtgtat aacacgttgc aatttaggtg gtgctgtctg tagacatcat 19501 gctaatgagt acagattgta tctcgatgct tataacatga tgatctcagc tggctttagc 19561 ttgtgggttt acaaacaatt tgatacttat aacctctgga acacttttac aagacttcag 19621 agtttagaaa atgtggcttt taatgttgta aataagggac actttgatgg acaacagggt 19681 gaagtaccag tttctatcat taataacact gtttacacaa aagttgatgg tgttgatgta 19741 gaattgtttg aaaataaaac aacattacct gttaatgtag catttgagct ttgggctaag 19801 cgcaacatta aaccagtacc agaggtgaaa atactcaata atttgggtgt ggacattgct 19861 gctaatactg tgatctggga ctacaaaaga gatgctccag cacatatatc tactattggt 19921 gtttgttcta tgactgacat agccaagaaa ccaactgaaa cgatttgtgc accactcact 19981 gtctifittg atggtagagt tgatggtcaa gtagacttat ttagaaatgc ccgtaatggt 20041 gttcttatta cagaaggtag tgttaaaggt ttacaaccat ctgtaggtcc caaacaagct 20101 agtcttaatg gagtcacatt aattggagaa gccgtaaaaa cacagttcaa ttattataag 20161 aaagttgatg gtgttgtcca acaattacct gaaacttact ttactcagag tagaaattta 20221 caagaattta aacccaggag tcaaatggaa attgatttct tagaattagc tatggatgaa 20281 ttcattgaac ggtataaatt agaaggctat gccttcgaac atatcgttta tggagatttt 20341 agtcatagtc agttaggtgg tttacatcta ctgattggac tagctaaacg ttttaaggaa 20401 tcaccttttg aattagaaga ttttattcct atggacagta cagttaaaaa ctatttcata 20461 acagatgcgc aaacaggttc atctaagtgt gtgtgttctg ttattgattt attacttgat 20521 gattttgttg aaataataaa atcccaagat ttatctgtag tttctaaggt tgtcaaagtg 20581 actattgact atacagaaat ttcatttatg ctttggtgta aagatggcca tgtagaaaca 20641 ttttacccaa aattacaatc tagtcaagcg tggcaaccgg gtgttgctat gcctaatctt 20701 tacaaaatgc aaagaatgct attagaaaag tgtgaccttc aaaattatgg tgatagtgca 20761 acattaccta aaggcataat gatgaatgtc gcaaaatata ctcaactgtg tcaatattta 20821 aacacattaa cattagctgt accctataat atgagagtta tacattttgg tgctggttct 20881 gataaaggag ttgcaccagg tacagctgtt ttaagacagt ggttgcctac gggtacgctg 20941 cttgtcgatt cagatcttaa tgactttgtc tctgatgcag attcaacttt gattggtgat 21001 tgtgcaactg tacatacagc taataaatgg gatctcatta ttagtgatat gtacgaccct 21061 aagactaaaa atgttacaaa agaaaatgac tctaaagagg gttttttcac ttacatttgt 21121 gggtttatac aacaaaagct agctcttgga ggttccgtgg ctataaagat aacagaacat 21181 tcttggaatg ctgatcttta taagctcatg ggacacttcg catggtggac agcctttgtt 21241 actaatgtga atgcgtcatc atctgaagca tttttaattg gatgtaatta tcttggcaaa 21301 ccacgcgaac aaatagatgg ttatgtcatg catgcaaatt acatattttg gaggaataca 21361 aatccaattc agttgtcttc ctattcttta tttgacatga gtaaatttcc ccttaaatta 21421 aggggtactg ctgttatgtc tttaaaagaa ggtcaaatca atgatatgat tttatctctt 21481 cttagtaaag gtagacttat aattagagaa aacaacagag ttgttatttc tagtgatgtt 21541 cttgttaaca actaaacgaa caatgtttgt ttttcttgtt ttattgccac tagtctctag 21601 tcagtgtgtt aatcttacaa ccagaactca attaccccct gcatacacta attctttcac 21661 acgtggtgtt tattaccctg acaaagtttt cagatcctca gttttacatt caactcagga 21721 cttgttctta cctttctttt ccaatgttac ttggttccat gctatacatg tctctgggac 21781 caatggtact aagaggtttg ataaccctgt cctaccattt aatgatggtg tttattttgc 21841 ttccactgag aagtctaaca taataagagg ctggattttt ggtactactt tagattcgaa 21901 gacccagtcc ctacttattg ttaataacgc tactaatgtt gttattaaag tctgtgaatt 21961 tcaattttgt aatgatccat ttttgggtgt ttattaccac aaaaacaaca aaagttggat 22021 ggaaagtgag ttcagagttt attctagtgc gaataattgc acttttgaat atgtctctca 22081 gccttttctt atggaccttg aaggaaaaca gggtaatttc aaaaatctta gggaatttgt 22141 gtttaagaat attgatggtt attttaaaat atattctaag cacacgccta ttaatttagt 22201 gcgtgatctc cctcagggtt tttcggcttt agaaccattg gtagatttgc caataggtat 22261 taacatcact aggtttcaaa ctttacttgc tttacataga agttatttga ctcctggtga 22321 ttcttcttca ggttggacag ctggtgctgc agcttattat gtgggttatc ttcaacctag 22381 gacttttcta ttaaaatata atgaaaatgg aaccattaca gatgctgtag actgtgcact 22441 tgaccctctc tcagaaacaa agtgtacgtt gaaatccttc actgtagaaa aaggaatcta 22501 tcaaacttct aactttagag tccaaccaac agaatctatt gttagatttc ctaatattac 22561 aaacttgtgc ccttttggtg aagtttttaa cgccaccaga tttgcatctg tttatgcttg 22621 gaacaggaag agaatcagca actgtgttgc tgattattct gtcctatata attccgcatc 22681 attttccact tttaagtgtt atggagtgtc tcctactaaa ttaaatgatc tctgctttac 22741 taatgtctat gcagattcat ttgtaattag aggtgatgaa gtcagacaaa tcgctccagg 22801 gcaaactgga aagattgctg attataatta taaattacca gatgatttta caggctgcgt 22861 tatagcttgg aattctaaca atcttgattc taaggttggt ggtaattata attacctgta 22921 tagattgttt aggaagtcta atctcaaacc ttttgagaga gatatttcaa ctgaaatcta 22981 tcaggccggt agcacacctt gtaatggtgt tgaaggtttt aattgttact ttcctttaca 23041 atcatatggt ttccaaccca ctaatggtgt tggttaccaa ccatacagag tagtagtact 23101 ttcttttgaa cttctacatg caccagcaac tgtttgtgga cctaaaaagt ctactaattt 23161 ggttaaaaac aaatgtgtca atttcaactt caatggttta acaggcacag gtgttcttac 23221 tgagtctaac aaaaagtttc tgcctttcca acaatttggc agagacattg ctgacactac 23281 tgatgctgtc cgtgatccac agacacttga gattcttgac attacac cat gttcttttgg 23341 tggtgtcagt gttataacac caggaacaaa tacttctaac caggttgctg ttctttatca 23401 ggatgttaac tgcacagaag tccctgttgc tattcatgca gatcaactta ctcctacttg 23461 gcgtgtttat tctacaggtt ctaatgtttt tcaaacacgt gcaggctgtt taataggggc 23521 tgaacatgtc aacaactcat atgagtgtga catacccatt ggtgcaggta tatgcgctag 23581 ttatcagact cagactaatt ctcctcggcg ggcacgtagt gtagctagtc aatccatcat 23641 tgcctacact atgtcacttg gtgcagaaaa ttcagttgct tactctaata actctattgc 23701 catacccaca aattttacta ttagtgttac cacagaaatt ctaccagtgt ctatgaccaa 23761 gacatcagta gattgtacaa tgtacatttg tggtgattca actgaatgca gcaatctttt 23821 gttgcaatat ggcagttttt gtacacaatt aaaccgtgct ttaactggaa tagctgttga 23881 acaagacaaa aacacccaag aagtttttgc acaagtcaaa caaatttaca aaacaccacc 23941 aattaaagat tttggtggtt ttaatttttc acaaatatta ccagatccat caaaaccaag 24001 caagaggtca tttattgaag atctactttt caacaaagtg acacttgcag atgctggctt 24061 catcaaacaa tatggtgatt gccttggtga tattgctgct agagacctca tttgtgcaca 24121 aaagtttaac ggccttactg ttttgccacc tttgctcaca gatgaaatga ttgctcaata 24181 cacttctgca ctgttagcgg gtacaatcac ttctggttgg acctttggtg caggtgctgc 24241 attacaaata ccatttgcta tgcaaatggc ttataggttt aatggtattg gagttacaca 24301 gaatgttctc tatgagaacc aaaaattgat tgccaaccaa tttaatagtg ctattggcaa 24361 aattcaagac tcactttctt ccacagcaag tgcacttgga aaacttcaag atgtggtcaa 24421 ccaaaatgca caagctttaa acacgcttgt taaacaactt agctccaatt ttggtgcaat 24481 ttcaagtgtt ttaaatgata tcctttcacg tcttgacaaa gttgaggctg aagtgcaaat 24541 tgataggttg atcacaggca gacttcaaag tttgcagaca tatgtgactc aacaattaat 24601 tagagctgca gaaatcagag cttctgctaa tcttgctgct actaaaatgt cagagtgtgt 24661 acttggacaa tcaaaaagag ttgatttttg tggaaagggc tatcatctta tgtccttccc 24721 tcagtcagca cctcatggtg tagtcttctt gcatgtgact tatgtccctg cacaagaaaa 24781 gaacttcaca actgctcctg ccatttgtca tgatggaaaa gcacactttc ctcgtgaagg 24841 tgtctttgtt tcaaatggca cacactggtt tgtaacacaa aggaattttt atgaaccaca 24901 aatcattact acagacaaca catttgtgtc tggtaactgt gatgttgtaa taggaattgt 24961 caacaacaca gtttatgatc ctttgcaacc tgaattagac tcattcaagg aggagttaga 25021 taaatatttt aagaatcata catcaccaga tgttgattta ggtgacatct ctggcattaa 25081 tgcttcagtt gtaaacattc aaaaagaaat tgaccgcctc aatgaggttg ccaagaattt 25141 aaatgaatct ctcatcgatc tccaagaact tggaaagtat gagcagtata taaaatggcc 25201 atggtacatt tggctaggtt ttatagctgg cttgattgcc atagtaatgg tgacaattat 25261 gctttgctgt atgaccagtt gctgtagttg tctcaagggc tgttgttctt gtggatcctg 25321 ctgcaaattt gatgaagacg actctgagcc agtgctcaaa ggagtcaaat tacattacac 25381 ataaacgaac ttatggattt gtttatgaga atcttcacaa ttggaactgt aactttgaag 25441 caaggtgaaa tcaaggatgc tactccttca gattttgttc gcgctactgc aacgataccg 25501 atacaagcct cactcccttt cggatggctt attgttggcg ttgcacttct tgctgttttt 25561 cagagcgctt ccaaaatcat aaccctcaaa aagagatggc aactagcact ctccaagggt 25621 gttcactttg tttgcaactt gctgttgttg tttgtaacag tttactcaca ccttttgctc 25681 gttgctgctg gccttgaagc cccttttctc tatctttatg ctttagtcta cttcttgcag 25741 agtataaact ttgtaagaat aataatgagg ctttggcttt gctggaaatg ccgttccaaa 25801 aacccattac tttatgatgc caactatttt ctttgctggc atactaattg ttacgactat 25861 tgtatacctt acaatagtgt aacttcttca attgtcatta cttcaggtga tggcacaaca 25921 agtcctattt ctgaacatga ctaccagatt ggtggttata ctgaaaaatg ggaatctgga 25981 gtaaaagact gtgttgtatt acacagttac ttcacttcag actattacca gctgtactca 26041 actcaattga gtacagacac tggtgttgaa catgttacct tcttcatcta caataaaatt 26101 gttgatgagc ctgaagaaca tgtccaaatt cacacaatcg acggttcatc cggagttgtt 26161 aatccagtaa tggaaccaat ttatgatgaa ccgacgacga ctactagcgt gcctttgtaa 26221 gcacaagctg atgagtacga acttatgtac tcattcgttt cggaagagac aggtacgtta 26281 atagttaata gcgtacttct ttttcttgct ttcgtggtat tcttgctagt tacactagcc 26341 atccttactg cgcttcgatt gtgtgcgtac tgctgcaata ttgttaacgt gagtcttgta 26401 aaaccttctt tttacgttta ctctcgtgtt aaaaatctga attcttctag agttcctgat 26461 cttctggtct aaacgaacta aatattatat tagtttttct gtttggaact ttaattttag 26521 ccatggcaga ttccaacggt actattaccg ttgaagagct taaaaagctc cttgaacaat 26581 ggaacctagt aataggtttc ctattcctta catggatttg tcttctacaa tttgcctatg 26641 ccaacaggaa taggtttttg tatataatta agttaatttt cctctggctg ttatggccag 26701 taactttagc ttgttttgtg cttgctgctg tttacagaat aaattggatc accggtggaa 26761 ttgctatcgc aatggcttgt cttgtaggct tgatgtggct cagctacttc attgettett 26821 tcagactgtt tgcgcgtacg cgttccatgt ggtcattcaa tccagaaact aacattcttc 26881 tcaacgtgcc actccatggc actattctga ccagaccgct tctagaaagt gaactcgtaa 26941 tcggagctgt gatccttcgt ggacatcttc gtattgctgg acaccatcta ggacgctgtg 27001 acatcaagga cctgcctaaa gaaatcactg ttgctacatc acgaacgctt tcttattaca 27061 aattgggagc ttcgcagcgt gtagcaggtg actcaggttt tgctgcatac agtcgctaca 27121 ggattggcaa ctataaatta aacacagacc attccagtag cagtgacaat attgctttgc 27181 ttgtacagta agtgacaaca gatgtttcat ctcgttgact ttcaggttac tatagcagag 27241 atattactaa ttattatgag gacttttaaa gtttccattt ggaatcttga ttacatcata 27301 aacctcataa ttaaaaattt atctaagtca ctaactgaga ataaatattc tcaattagat 27361 gaagagcaac caatggagat tgattaaacg aacatgaaaa ttattctttt cttggcactg 27421 ataacactcg ctacttgtga gctttatcac taccaagagt gtgttagagg tacaacagta 27481 cttttaaaag aaccttgctc ttctggaaca tacgagggca attcaccatt tcatcctcta 27541 gctgataaca aatttgcact gacttgcttt agcactcaat ttgcttttgc ttgtcctgac 27601 ggcgtaaaac acgtctatca gttacgtgcc agatcagttt cacctaaact gttcatcaga 27661 caagaggaag ttcaagaact ttactctcca atttttctta ttgttgcggc aatagtgttt 27721 ataacacttt gcttcacact caaaagaaag acagaatgat tgaactttca ttaattgact 27781 tctatttgtg ctttttagcc tttctgctat tccttgtttt aattatgctt attatctttt 27841 ggttctcact tgaactgcaa gatcataatg aaacttgtca cgcctaaacg aacatgaaat 27901 ttcttgtttt cttaggaatc atcacaactg tagctgcatt tcaccaagaa tgtagtttac 27961 agtcatgtac tcaacatcaa ccatatgtag ttgatgaccc gtgtcctatt cacttctatt 28021 ctaaatggta tattagagta ggagctagaa aatcagcacc tttaattgaa ttgtgcgtgg 28081 atgaggctgg ttctaaatca cccattcagt acatcgatat cggtaattat acagtttcct 28141 gtttaccttt tacaattaat tgccaggaac ctaaattggg tagtcttgta gtgcgttgtt 28201 cgttctatga agacttttta gagtatcatg acgttcgtgt tgttttagat ttcatctaaa 28261 cgaacaaact aaaatgtctg ataatggacc ccaaaatcag cgaaatgcac cccgcattac 28321 gtttggtgga ccctcagatt caactggcag taaccagaat ggagaacgca gtggggcgcg 28381 atcaaaacaa cgtcggcccc aaggtttacc caataatact gcgtcttggt tcaccgctct 28441 cactcaacat ggcaaggaag accttaaatt ccctcgagga caaggcgttc caattaacac 28501 caatagcagt ccagatgacc aaattggcta ctaccgaaga gctaccagac gaattcgtgg 28561 tggtgacggt aaaatgaaag atctcagtcc aagatggtat ttctactacc taggaactgg 28621 gccagaagct ggacttccct atggtgctaa caaagacggc atcatatggg ttgcaactga 28681 gggagccttg aatacaccaa aagatcacat tggcacccgc aatcctgcta acaatgctgc 28741 aatcgtgcta caacttcctc aaggaacaac attgccaaaa ggcttctacg cagaagggag 28801 cagaggcggc agtcaagcct cttctcgttc ctcatcacgt agtcgcaaca gttcaagaaa 28861 ttcaactcca ggcagcagta ggggaacttc tcctgctaga atggctggca atggcggtga 28921 tgctgctctt gctttgctgc tgcttgacag attgaaccag cttgagagca aaatgtctgg 28981 taaaggccaa caacaacaag gccaaactgt cactaagaaa tctgctgctg aggcttctaa 29041 gaagcctcgg caaaaacgta ctgccactaa agcatacaat gtaacacaag ctttcggcag 29101 acgtggtcca gaacaaaccc aaggaaattt tggggaccag gaactaatca gacaaggaac 29161 tgattacaaa cattggccgc aaattgcaca atttgccccc agcgcttcag cgttcttcgg 29221 aatgtcgcgc attggcatgg aagtcacacc ttcgggaacg tggttgacct acacaggtgc 29281 catcaaattg gatgacaaag atccaaattt caaagatcaa gtcattttgc tgaataagca 29341 tattgacgca tacaaaacat tcccaccaac agagcctaaa aaggacaaaa agaagaaggc 29401 tgatgaaact caagccttac cgcagagaca gaagaaacag caaactgtga ctcttcttcc 29461 tgctgcagat ttggatgatt tctccaaaca attgcaacaa tccatgagca gtgctgactc 29521 aactcaggcc taaactcatg cagaccacac aaggcagatg ggctatataa acgttttcgc 29581 ttttccgttt acgatatata gtctactctt gtgcagaatg aattctcgta actacatagc 29641 acaagtagat gtagttaact ttaatctcac atagcaatct ttaatcagtg tgtaacatta 29701 gggaggactt gaaagagcca ccacattttc accgaggcca cgcggagtac gatcgagtgt 29761 acagtgaaca atgctaggga gagctgccta tatggaagag ccctaatgtg taaaattaat 29821 tttagtagtg ctatccccat gtgattttaa tagcttctta ggagaatgac aaaaaaaaaa 29881 aaaaaaaaaa aaaaaaaaaa aaa Wuhan 164 MESLVPGFNEKTHVQLSLPVLQVRDVLVRGF seafood GDSVEEVLSEARQHLKDGTCGLVEVEKGVLP market QLEQPYVFIKRSDARTAPHGHVMVELVAELE pneumonia GIQYGRSGETLGVLVPHVGEIPVAYRKVLLR virus isolate KNGNKGAGGHSYGADLKSFDLGDELGTDPY Wuhan-Hu-1 EDFQENWNTKHSSGVTRELMRELNGGAYTR genomic YVDNNFCGPDGYPLECIKDLLARAGKASCTL sequence SEQLDFIDTKRGVYCCREHEHEIAWYTERSEK (GenBank: SYELQTPFEIKLAKKEDTENGECPNFVFPLNSII MN908947.3; KTIQPRVEKKKLDGFMGRIRSVYPVASPNECN Jan. 23 , QMCLSTLMKCDHCGETSWQTGDFVKATCEF 2020) - amino CGTENLTKEGATTCGYLPQNAVVKIYCPACH acid NSEVGPEHSLAEYHNESGLKTILRKGGRTIAF translation GGCVFSYVGCHNKCAYWVPRASANIGCNHT GVVGEGSEGLNDNLLEILQKEKVNINIVGDFK LNEEIAIILASFSASTSAFVETVKGLDYKAFKQ IVESCGNFKVTKGKAKKGAWNIGEQKSILSPL YAFASEAARVVRSIFSRTLETAQNSVRVLQKA AITILDGISQYSLRLIDAMMFTSDLATNNLVV MAYITGGVVQLTSQWLTNIFGTVYEKLKPVL DWLEEKFKEGVEFLRDGWEIVKFISTCACEIV GGQIVTCAKEIKESVQTFFKLVNKFLALCADS IIIGGAKLKALNLGETFVTHSKGLYRKCVKSR EETGLLMPLKAPKEIIFLEGETLPTEVLTEEVV LKTGDLQPLEQPTSEAVEAPLVGTPVCINGLM LLEIKDTEKYCALAPNMMVTNNTFTLKGGAP TKVTFGDDTVIEVQGYKSVNITFELDERIDKV LNEKCSAYTVELGTEVNEFACVVADAVIKTL QPVSELLTPLGIDLDEWSMATYYLFDESGEFK LASHMYCSFYPPDEDEEEGDCEEEEFEPSTQY EYGTEDDYQGKPLEFGATSAALQPEEEQEED WLDDDSQQTVGQQDGSEDNQTTTIQTIVEVQ PQLEMELTPVVQTIEVNSFSGYLKLTDNVYIK NADIVEEAKKVKPTVVVNAANVYLKHGGGV AGALNKATNNAMQVESDDYIATNGPLKVGG SCVLSGHNLAKHCLHVVGPNVNKGEDIQLLK SAYENFNQHEVLLAPLLSAGIFGADPIHSLRV CVDTVRTNVYLAVFDKNLYDKLVSSFLEMKS EKQVEQKIAEIPKEEVKPFITESKPSVEQRKQD DKKIKACVEEVTTTLEETKFLTENLLLYIDING NLHPDSATLVSDIDITFLKKDAPYIVGDVVQE GVLTAVVIPTKKAGGTTEMLAKALRKVPTDN YITTYPGQGLNGYTVEEAKTVLKKCKSAFYIL PSIISNEKQEILGTVSWNLREMLAHAEETRKL MPVCVETKAIVSTIQRKYKGIKIQEGVVDYGA RFYFYTSKTTVASLINTLNDLNETLVT1VIPLGY VTHGLNLEEAARYMRSLKVPATVSVSSPDAV TAYNGYLTSSSKTPEEHFIETISLAGSYKDWS YSGQSTQLGIEFLKRGDKSVYYTSNPTTFHLD GEVITFDNLKTLLSLREVRTIKVFTTVDNINLH TQVVDMSMTYGQQFGPTYLDGADVTKIKPH NSHEGKTFYVLPNDDTLRVEAFEYYHTTDPS FLGRYMSALNHTKKWKYPQVNGLTSIKWAD NNCYLATALLTLQQIELKFNPPALQDAYYRA RAGEAANFCALILAYCNKTVGELGDVRETMS YLFQHANLDSCKRVLNVVCKTCGQQQTTLK GVEAVMYMGTLSYEQFKKGVQIPCTCGKQA TKYLVQQESPFVMMSAPPAQYELKHGTFTCA SEYTGNYQCGHYKHITSKETLYCIDGALLTKS SEYKGPITDVFYKENSYTTTIKPVTYKLDGVV CTEIDPKLDNYYKKDNSYFTEQPIDLVPNQPY PNASFDNFKFVCDNIKFADDLNQLTGYKKPA SRELKVTFFPDLNGDVVAIDYKHYTPSFKKG AKLLHKPIVWHVNNATNKATYKPNTWCIRC LWSTKPVETSNSFDVLKSEDAQGMDNLACED LKPVSEEVVENPTIQKDVLECNVKTTEVVGDI ILKPANNSLKITEEVGHTDLMAAYVDNSSLTI KKPNELSRVLGLKTLATHGLAAVNSVPWDTI ANYAKPFLNKVVSTTTNIVTRCLNRVCTNYM PYFFTLLLQLCTFTRSTNSRIKASMPTTIAKNT VKSVGKFCLEASFNYLKSPNFSKLINIIIWFLL LSVCLGSLIYSTAALGVLMSNLGMPSYCTGY REGYLNSTNVTIATYCTGSIPCSVCLSGLDSLD TYPSLETIQITISSFKWDLTAFGLVAEWFLAYI LFTRFFYVLGLAAIMQLFFSYFAVHFISNSWL MWLIINLVQMAPISAMVRMYIFFASFYYVWK SYVHVVDGCNSSTCMMCYKRNRATRVECTT IVNGVRRSFYVYANGGKGFCKLHNWNCVNC DTFCAGSTFISDEVARDLSLQFKRPINPTDQSS YIVDSVTVKNGSIHLYFDKAGQKTYERHSLS HFVNLDNLRANNTKGSLPINVIVFDGKSKCEE SSAKSASVYYSQLMCQPILLLDQALVSDVGD SAEVAVKMFDAYVNTFSSTFNVPMEKLKTLV ATAEAELAKNVSLDNVLSTFISAARQGFVDS DVETKDVVECLKLSHQSDIEVTGDSCNNYML TYNKVENMTPRDLGACIDCSARHINAQVAKS HNIALIWNVKDFMSLSEQLRKQIRSAAKKNN LPFKLTCATTRQVVNVVTTKIALKGGKIVNN WLKQLIKVTLVFLFVAAIFYLITPVHVMSKHT DFSSEIIGYKAIDGGVTRDIASTDTCFANKHA DFDTWFSQRGGSYTNDKACPLIAAVITREVGF VVPGLPGTILRTTNGDFLHFLPRVFSAVGNIC YTPSKLIEYTDFATSACVLAAECTIFKDASGK PVPYCYDTNVLEGSVAYESLRPDTRYVLMDG SIIQFPNTYLEGSVRVVTTFDSEYCRHGTCERS EAGVCVSTSGRWVLNNDYYRSLPGVFCGVD AVNLLTNMFTPLIQPIGALDISASIVAGGIVAI VVTCLAYYFMRFRRAFGEYSHVVAFNTLLFL MSFTVLCLTPVYSFLPGVYSVIYLYLTFYLTN DVSFLAHIQWMVMFTPLVPFWITIAYIICISTK HFYWFFSNYLKRRVVFNGVSFSTFEEAALCTF LLNKEMYLKLRSDVLLPLTQYNRYLALYNK YKYFSGAMDTTSYREAACCHLAKALNDFSNS GSDVLYQPPQTSITSAVLQSGFRKMAFPSGKV EGCMVQVTCGTTTLNGLWLDDVVYCPRHVI CTSEDMLNPNYEDLLIRKSNHNFLVQAGNVQ LRVIGHSMQNCVLKLKVDTANPKTPKYKFVR IQPGQTFSVLACYNGSPSGVYQCAMRPNFTIK GSFLNGSCGSVGFNIDYDCVSFCYMEIHMELP TGVHAGTDLEGNFYGPFVDRQTAQAAGTDT TITVNVLAWLYAAVINGDRWFLNRFTTTLND FNLVAMKYNYEPLTQDHVDILGPLSAQTGIA VLDMCASLKELLQNGMNGRTILGSALLEDEF TPFDVVRQCSGVTFQSAVKRTIKGTHEWLLL TILTSLLVLVQSTQWSLFFFLYENAFLPFAMGI IAMSAFAM1VIFVKHKHAFLCLFLLPSLATVAY FNMVYMPASWVMRIMTWLDMVDTSLSGFK LKDCVMYASAVVLLILMTARTVYDDGARRV WTLMNVLTLVYKVYYGNALDQAISMWALII SVTSNYSGVVTTVMFLARGIVFMCVEYCPIFF ITGNTLQCIMLVYCFLGYFCTCYFGLFCLLNR YFRLTLGVYDYLVSTQEFRYMNSQGLLPPKN SIDAFKLNIKLLGVGGKPCIKVATVQSKMSDV KCTSVVLLSVLQQLRVESSSKLWAQCVQLHN DILLAKDTTEAFEKMVSLLSVLLSMQGAVDI NKLCEEMLDNRATLQAIASEFSSLPSYAAFAT AQEAYEQAVANGDSEVVLKKLKKSLNVAKS EFDRDAAMQRKLEKMADQAMTQMYKQARS EDKRAKVTSAMQTMLFTMLRKLDNDALNNII NNARDGCVPLNIIPLTTAAKLMVVIPDYNTYK NTCDGTTFTYASALWEIQQVVDADSKIVQLS EISMDNSPNLAWPLIVTALRANSAVKLQNNE LSPVALRQMSCAAGTTQTACTDDNALAYYN TTKGGRFVLALLSDLQDLKWARFPKSDGTGT IYTELEPPCRFVTDTPKGPKVKYLYFIKGLNN LNRGMVLGSLAATVRLQAGNATEVPANSTV LSFCAFAVDAAKAYKDYLASGGQPITNCVK MLCTHTGTGQAITVTPEANMDQESFGGASCC LYCRCHIDHPNPKGFCDLKGKYVQIPTTCAN DPVGFTLKNTVCTVCGMWKGYGCSCDQLRE PMLQSADAQSFLNRVCGVSAARLTPCGTGTS TDVVYRAFDIYNDKVAGFAKFLKTNCCRFQE KDEDDNLIDSYFVVKRHTFSNYQHEETIYNLL KDCPAVAKHDFFKFRIDGDMVPHISRQRLTK YTMADLVYALRHFDEGNCDTLKEILVTYNCC DDDYFNKKDWYDFVENPDILRVYANLGERV RQALLKTVQFCDAMRNAGIVGVLTLDNQDL NGNWYDFGDFIQTTPGSGVPVV DSYYSLUVIPILTLTRALTAESHVDTDLTKPYI KWDLLKYDFTEERLKLFDRYFKYWDQTYHP NCVNCLDDRCILHCANFNVLFSTVFPPTSFGP LVRKIFVDGVPFVVSTGYHFRELGVVHNQDV NIBSSRLSFKELLVYAADPAMHAASGNLLLD KRTTCFSVAALTNNVAFQTVKPGNFNKDFYD FAVSKGFFKEGSSVELKHFFFAQDGNAAISDY DYYRYNLPTMCDIRQLLFVVEVVDKYFDCY DGGCINANQVIVNNLDKSAGFPFNKWGKARL YYDSMSYEDQDALFAYTKRNVIPTITQMNLK YAISAKNRARTVAGVSICSTMTNRQFHQKLL KSIAATRGATVVIGTSKFYGGWHNMLKTVYS DVENPHLMGWDYPKCDRA1VIPNMLRIMASL VLARKHTTCCSLSHRFYRLANECAQVLSEMV MCGGSLYVKPGGTSGDATTAYANSVFNICQ AVTANVNALLSTDGNKIADKYVRNLQHRLY ECLYRNRDVDTDFVNEFYAYLRKHFSMMILS DDAVVCFNSTYASQGLVASIKNFKSVLYYQN NVFMSEAKCWTETDLTKGPHEFCSQHTMLV KQGDDYVYLPYPDPSRILGAGCFVDDIVKTD GTLMIERFVSLAIDAYPLTKHPNQEYADVFHL YLQYIRKLHDELTGHMLDMYSVMLTNDNTS RYWEPEFYEAMYTPHTVLQAVGACVLCNSQ TSLRCGACIRRPFLCCKCCYDHVISTSHKLVL SVNPYVCNAPGCDVTDVTQLYLGGMSYYCK SHKPPISFPLCANGQVFGLYKNTCVGSDNVTD FNAIATCDWTNAGDYILANTCTERLKLFAAE TLKATEETFKLSYGIATVREVLSDRELHLSWE VGKPRPPLNRNYVFTGYRVTKNSKVQIGEYT FEKGDYGDAVVYRGTTTYKLNVGDYFVLTS HTVMPLSAPTLVPQEHYVRITGLYPTLNISDE FSSNVANYQKVGMQKYSTLQGPPGTGKSHF AIGLALYYPSARIVYTACSHAAVDALCEKAL KYLPIDKCSRIIPARARVECFDKFKVNSTLEQY VFCTVNALPETTADIVVFDEISMATNYDLSVV NARLRAKHYVYIGDPAQLPAPRTLLTKGTLE PEYFNSVCRLMKTIGPD1VIFLGTCRRCPAEIVD TVSALVYDNKLKAHKDKSAQCFK1VIFYKGVI THDVSSAINRPQIGVVREFLTRNPAWRKAVFI SPYNSQNAVASKILGLPTQTVDSSQGSEYDYV IFTQTTETAHSCNVNRFNVAITRAKVGILCIMS DRDLYDKLQFTSLEIPRRNVATLQAENVTGLF KDCSKVITGLHPTQAPTHLSVDTKFKTEGLCV DIPGIPKDMTYRRLISMMGFKMNYQVNGYPN MFITREEAIRHVRAWIGFDVEGCHATREAVG TNLPLQLGFSTGVNLVAVPTGYVDTPNNTDF SRVSAKPPPGDQFKHLIPLMYKGLPWNVVRI KIVQMLSDTLKNLSDRVVFVLWAHGFELTSM KYFVKIGPERTCCLCDRRATCFSTASDTYAC WHHSIGFDYVYNPFMIDVQQWGFTGNLQSN HDLYCQVHGNAHVASCDAIIVITRCLAVHECF VKRVDWTIEYPIIGDELKINAACRKVQHMVV KAALLADKFPVLHDIGNPKAIKCVPQADVEW KFYDAQPCSDKAYKIEELFYSYATHSDKFTD GVCLFWNCNVDRYPANSIVCRFDTRVLSNLN LPGCDGGSLYVNKHAFHTPAFDKSAFVNLKQ LPFFYYSDSPCESHGKQVVSDIDYVPLKSATCI TRCNLGGAVCRHHANEYRLYLDAYNMMISA GFSLWVYKQFDTYNLWNTFTRLQSLENVAF NVVNKGHFDGQQGEVPVSIINNTVYTKVDGV DVELFENKTTLPVNVAFELWAKRNIKPVPEV KILNNLGVDIAANTVIWDYKRDAPAHISTIGV CSMTDIAKKPTETICAPLTVFFDGRVDGQVDL FRNARNGVLITEGSVKGLQPSVGPKQASLNG VTLIGEAVKTQFNYYKKVDGVVQQLPETYFT QSRNLQEFKPRSQMEIDFLELAMDEFIERYKL EGYAFEHIVYGDFSHSQLGGLHLLIGLAKRFK ESPFELEDFIPMDSTVKNYFITDAQTGSSKCVC SVIDLLLDDFVEIIKSQDLSVVSKVVKVTIDYT EISFMLWCKDGHVETFYPKLQSSQAWQPGVA MPNLYKMQRMLLEKCDLQNYGDSATLPKGI MMNVAKYTQLCQYLNTLTLAVPYNMRVIHF GAGSDKGVAPGTAVLRQWLPTGTLLVDSDL NDFVSDADSTLIGDCATVHTANKWDLIISDM YDPKTKNVTKENDSKEGFFTYICGFIQQKLAL GGSVAIKITEHSWNADLYKLMGHFAWWTAF VTNVNASSSEAFLIGCNYLGKPREQIDGYVM HANYIFWRNTNPIQLSSYSLFDMSKFPLKLRG TAVMSLKEGQINDMILSLLSKGRLIIRENNRV VISSDVLVNN surface 165 mfvflvllpl vssqcvnltt rtqlppaytn sftrgvyypd glycoprotein kvfrssvlhs tqdlflpffs 61 nvtwfhaihv sgtngtkrfd [Wuhan npvlpfndgv yfasteksni irgwifgttl dsktqslliv 121 seafood nnatnvvikv cefqfcndpf lgvyyhknnk swmesefrvy market ssannctfey vsqpflmdle181 gkqgnflcnlr efvfknidgy pneumonia fkiyskhtpi nlvrdlpqgf saleplvdlp iginitrfqt 241 virus]; llalhrsylt pgdsssgwta gaaayyvgyl qprtfllkyn GenBank: engtitdavd caldplsetk 301 ctlksftvek giyqtsnfry QHD43416.1; qptesivrfp nitnlcpfge vfnatrfasv yawnrkrisn 361 Jan. 23, cvadysvlyn sasfstfkcy gvsptklndl cftnvyadsf 2020 virgdevrqi apgqtgkiad 421 ynyklpddft gcviawnsnn ldskvggnyn ylyrlfrksn lkpferdist eiyqagstpc 481 ngvegfncyf plqsygfqpt ngvgyqpyry vvlsfellha patvcgpkks tnlvknkcvn 541 fnfngltgtg vltesnkkfl pfqqfgrdia dttdavrdpq tleilditpc sfggvsvitp 601 gtntsnqvav lyqdvnctev pvaihadqlt ptwrvystgs nvfqtragcl igaehvnnsy 661 ecdipigagi casyqtqtns prrarsvasq siiaytmslg aensvaysnn siaiptnfti 721 svtteilpvs mtktsvdctm yicgdstecs nlllqygsfc tqlnraltgi aveqdkntqe 781 vfaqvkqiyk tppikdfggf nfsqilpdps kpskrsfied llfnkvtlad agfikqygdc 841 lgdiaardli caqkfngltv lpplltdemi aqytsallag titsgwtfga gaalqipfam 901 qmayrfngig vtqnvlyenq klianqfnsa igkiqdslss tasalgklqd vvnqnaqaln 961 tivkqlssnf gaissvindi lsrldkveae vqidrlitgr lqslqtyvtq qliraaeira 1021 sanlaatkms ecvlgqskry dfcgkgyhlm sfpqsaphgv vflhvtyvpa qeknfttapa 1081 ichdgkahfp regvfvsngt hwfvtqrnfy epqiittdnt fvsgncdvvi givnntvydp 1141 lqpeldsfke eldkyfknht spdvdlgdis ginasvvniq keidrineva knlneslidl 1201 qelgkyeqyi kwpwyiwlgf iagliaivmv timlccmtsc csclkgccsc gscckfdedd 1261 sepvlkgvkl hyt surface 166 nitnlcpfgevfnatrfasvyawnrkrisncvadysvlynsasfstfkc glycoprotein ygvsptklndleftnvyadsfvirgdevrqiapgqtgkiadynyklpd RBD [Wuhan dftgcviawnsnnldskvggnynylyrlfrksnlkpferdisteiyqa seafood gstpcngvegfncyfplqsygfqptngvgyqpyrvvvlsfellhapa market tvcgpkkstnlvknkcvnfnfngltgtg pneumonia virus]; GenBank: QHD43416.1; Jan. 23, 2020 Receptor 167 Nsnnldskvggnynylyrlfrksnlkpferdisteiyqagstpcngve Binding Motif gfncyfplqsygfqptngvgyqpy (RBM) in surface glycoprotein RBD [Wuhan seafood market pneumonia virus]; GenBank: QHD43416.1; Jan. 23, 2020 SARS-CoV-2 168 EIVLTQSPGTLSLSPGERATLSCRASQTVSSTS S309-v13 LAWYQQKPGQAPRLLIYGASSRATGIPDRFSG mAb VL (Vκ) SGSGTDFTLTISRLEPEDFAVYYCQQHDTSLT (aa) FGGGTKVEIK SARS-CoV-2 169 QTVSSTS S309-v13 mAb CDRL1 (aa) SARS-CoV-2 170 GAS S309-v13 mAb CDRL2 (aa) SARS-CoV-2 171 QQHDTSLT S309-v13 mAb CDRL3 (aa) SARS-CoV-2 172 QVQLVQSGAEVKKPGASVKVSCKASGYPFT S309-v2.9 SYGISWVRQAPGQGLEWMGFISTYNANTNY mAb VH (aa) AQKFQGRVTMTTDTSTTTGYMELRRLRSDDT AVYYCARDYTRGAFFGESLIGGFDNWGQG TLVTVSS SARS-CoV-2 173 ASTKGPSVFPLAPSSKSTSGGTAALGCLVKDY CH1-CH3 FPEPVTVSWNSGALTSGVHTFPAVLQSSGLYS G1m17; LSSVVTVPSSSLGTQTYICNVNHKPSNTKVDK IgG1*01 LS KVEPKSCDKTHTCPPCPAPELLGGPSVFLFPP (aa) KPKDTLMISRTPEVTCVVVDVSHEDPEVKFN WYVDGVEVHNAKTKPREEQYNSTYRVVSVL TVLHQDWLNGKEYKCKVSNKALPAPIEKTIS KAKGQPREPQVYTLPPSRDELTKNQVSLTCL VKGFYPSDIAVEWESNGQPENNYKTTPPVLD SDGSFFLYSKLTVDKSRWQQGNVFSCSVLHE ALHSHYTQKSLSLSPGK SARS-CoV-2 174 RTVAAPSVFIFPPSDEQLKSGTASVVCLLNNF mAb CL (Ck) YPREAKVQWKVDNALQSGNSQESVTEQDSK IgKC*01 DSTYSLSSTLTLSKADYEKHKVYACEVTHQG k1m3 (aa) LSSPVTKSFNRGEC SARS-CoV-2 175 ASTKGPSVFPLAPSSKSTSGGTAALGCLVKDY CH1-CH3 FPEPVTVSWNSGALTSGVHTFPAVLQSSGLYS G1m17; LSSVVTVPSSSLGTQTYICNVNHKPSNTKVDK IgG1*01 LS KVEPKSCDKTHTCPPCPAPELLAGPSVFLFPP GAALIE (aa) KPKDTLMISRTPEVTCVVVDVSHEDPEVKFN WYVDGVEVHNAKTKPREEQYNSTYRVVSVL TVLHQDWLNGKEYKCKVSNKALPLPEEKTIS KAKGQPREPQVYTLPPSRDELTKNQVSLTCL VKGFYPSDIAVEWESNGQPENNYKTTPPVLD SDGSFFLYSKLTVDKSRWQQGNVFSCSVLHE ALHSHYTQKSLSLSPGK SARS-CoV-2 176 QVQLVQSGAEVKKPGASVKVSCKASGYTFT S300-v2.10 DYYIHWVRQAPGQGPEWLGFVNAYSGATRY mAb VH (aa) AQKYQGRVTMTRDTSISTAYMQLSRLRPDDT AVYYCARDRPSHEFAMYFFDNWGQGTLVT VSS SARS-CoV-2 177 QVQLVQSGAEVKKPGASVKVSCKASGYTFT S300-v2.11 DYYIEWVRQAPGQGPEWLGFVQGYSGATRY mAb VH (aa) AQKYQGRVTMTRDTSISTAYMQLSRLRPDDT AVYYCARDRPSHEFAMYFFDNWGQGTLVT VSS SARS-CoV-2 178 EVQLVESGGGLVQPGGSLRLSCAASGFTFSN S315-v1 mAb YWMTWVRQAPGKGLEWVANIKQDGSEKY VH (aa) YVDSVKGRFTISRDNAKNSLYLQMNSLRAED TAVYYCARDLWWNDQAHYYGMDVWGQG TTVTVSS SARS-CoV-2 179 GFTFSNYW S315-v1 mAb CDRH1 (aa) SARS-CoV-2 180 IKQDGSEK S315-v1 mAb CDRH2 (aa) SARS-CoV-2 181 ARDLWWNDQAHYYGMDV S315-v1 mAb CDRH3 (aa) SARS-CoV-2 182 SYELTQPPSVSVSPGQTARITCSGDA F P N QYA S315-v1 mAb YWYQQKPGQAPVMLIYKDSERPSGIPERFFGS VL (aa) SSGTTVTLTIRGVQAEDEADYYCQSADSSGT VFGGGTKLTVL SARS-CoV-2 183 AFPNQY S315-v1 mAb CDRL1 (aa) SARS-CoV-2 184 KDS S315-v1 mAb CDRL2 (aa) SARS-CoV-2 185 QSADSSGTV S315-v1 mAb CDRL3 (aa) SARS-CoV-2 186 gaggtgcagctggtggagtctgggggaggcttggtccagcctggggg S315-v1 mAb gtecctgagactctectgtgcagcctctggattcacctttagtaattatt VH (nt − wt) ggatgacctgggtccgccaggctccagggaaggggctggagtgggt ggccaacataaagcaagatggaagtgagaaatactatgtggactct gtgaagggccgattcaccatctccagagacaacgccaagaactcactg tatctgcaaatgaacagcctgagagccgaggacacggctgtgtattact gtgcgagagatctttggtggaacgaccaggctcactactacggtat ggacgtctggggccaagggaccacggtcaccgtctcctcag SARS-CoV-2 187 tcctatgagctgacacagccaccctcggtgtcagtgtccccaggacag S315-v1 mAb acggccaggatcacctgctctggagatgcattcccaaaccaatatgct VL (nt − wt) tattggtaccagcagaagccaggccaggcccctgtgatgctgatctata aagacagtgagaggccctcagggatccctgagcgattctttggctcca gctcagggacaacagtcacgttgaccatcagaggagtccaggcagaa gacgaggctgactattactgtcaatcagcagacagcagtggtaccgt gttcggcggagggaccaagctgaccgtcctag SARS-CoV-2 188 GAAGTGCAGCTTGTCGAGAGCGGCGGAGG S315-v1 mAb CCTCGTTCAGCCAGGTGGGAGTCTCCGTCTT VH (nt - TCATGCGCCGCTTCAGGATTTACGTTCTCC codon AACTACTGGATGACATGGGTGAGGCAGGC optimized) ACCTGGGAAGGGGCTGGAGTGGGTGGCTA ACATCAAGCAGGACGGATCTGAAAAATAT TATGTAGATTCTGTGAAGGGGCGGTTTACC ATCTCAAGGGATAATGCCAAAAACTCTTTG TATTTACAGATGAACTCTCTTCGAGCCGAG GACACCGCCGTTTACTACTGTGCCCGAGA TCTATGGTGGAATGACCAGGCTCACTATT ATGGAATGGACGTGTGGGGCCAGGGTACT ACCGTTACCGTCTCCTCA SARS CoV-2 189 TCTTACGAGCTCACCCAGCCACCCTCAGTG S315-v1 mAb TCAGTGAGCCCTGGCCAAACAGCTCGCATC VL (nt- codon ACCTGTTCAGGTGACGCCTTTCCAAATCA optimized) GTACGCCTACTGGTATCAGCAGAAACCCGG CCAGGCACCCGTTATGCTCATCTACAAAGA TTCTGAGCGGCCATCCGGTATCCCCGAACG CTTTTTCGGAAGCTCCAGTGGGACTACAGT TACACTTACTATCCGGGGAGTGCAAGCTGA AGATGAGGCCGACTATTATTGCCAGAGCG CAGACTCCTCAGGCACAGTGTTTGGGGGC GGGACTAAACTAACTGTGCTG SARS CoV-2 190 SYELTQPPSVSVSPGQTARITCSGDAFPNQYA S315-v2 mAb YWYQQKPGQAPVMLIYKDSERPSGIPERFFGS VL (aa) SSGTTVTLTISGVQAEDEADYYCQSADSSGT VFGGGTKLTVL SARS-CoV-2 191 tcctatgagctgacacagccaccctcggtgtcagtgtccccaggacag S315-v2 mAb acggccaggatcacctgctctggagatgcattcccaaaccaatatgct VL (nt-wt) tattggtaccagcagaagccaggccaggcccctgtgatgctgatctata aagacagtgagaggccctcagggatccctgagcgattctttggctcca gctcagggacaacagtcacgttgaccatcagtggagtccaggcagaa gacgaggctgactattactgtcaatcagcagacagcagtggtaccgt gttcggcggagggaccaagctgaccgtcctag SARS-CoV-2 192 TCCTACGAGCTCACCCAGCCCCCCTCAGTCT S315-v2 mAb CTGTGTCTCCTGGACAGACAGCCAGAATCA VL (nt - CCTGCTCGGGAGATGCTTTTCCCAACCAA codon TACGCCTACTGGTACCAACAGAAACCAGGT optimized) CAGGCGCCTGTCATGCTGATTTATAAAGAC TCAGAGCGGCCTTCAGGAATTCCCGAAAGA TTCTTCGGGAGTTCAAGCGGAACTACCGTG ACCTTAACCATAAGCGGGGTGCAGGCCGAA GATGAAGCAGACTATTATTGCCAGAGTGC CGATAGTAGTGGCACAGTCTTTGGGGGGG GGACAAAGCTGACAGTACTC SARS-CoV-2 193 GQPKAAPSVTLFPPSSEELQANKATLVCLISDF mAb CL YPGAVTVAWKADSSPVKAGVETTTPSKQSN IgLC*01 NKYAASSYLSLTPEQWKSHRSYSCQVTHEGS TVEKTVAPTECS SARS-CoV-2 194 EVQLVESGGGLVQPGGSLRLSCAASGFTFS N S315-v3 mAb YFMTWVRQAPGKGLEWVANIKQDGSEKYY VH (aa) VDSVKGRFTISRDNAKNSLYLQMNSLRAEDT AVYYCARDLWWNDQAHYYGMDVWGQGT TVTVSS SARS-CoV-2 195 GFTFSNYF S315-v3 mAb CDRH1 (aa) SARS-CoV-2 196 EVQLVESGGGLVQPGGSLRLSCAASGFTFS N S315-v4 mAb YWMTWVRQAPGKGLEWVANIKQDASEKY VH (aa) YVDSVKGRFTISRDNAKNSLYLQMNSLRAED TAVYYCARDLWWNDQAHYYGMDVWGQG TTVTVSS SARS-CoV-2 197 IKQDASEK S315-v4 mAb CDRH2 (aa) SARS-CoV-2 198 EVQLVESGGGLVQPGGSLRLSCAASGFTFS N S315-v5 mAb YWMTWVRQAPGKGLEWVANIKQEGSEKY VH (aa) YVDSVKGRFTISRDNAKNSLYLQMNSLRAED TAVYYCARDLWWNDQAHYYGMDVWGQG TTVTVSS SARS-CoV-2 199 IKQEGSEK S315-v5 mAb CDRH2 (aa) SARS-CoV-2 200 EVQLVESGGGLVQPGGSLRLSCAASGFTFSN S315-v6 mAb YWMTWVRQAPGKGLEWVANIKQDGSEKY VH (aa) YVDSVKGRFTISRDNAKNSLYLQMNSLRAED TAVYYCARDLFWNDQAHYYGMDVWGQGT TVTVSS SARS-CoV-2 201 ARDLFWNDQAHYYGMDV S315-v6 mAb CDRH3 (aa) SARS-CoV-2 202 EVQLVESGGGLVQPGGSLRLSCAASGFTFSN S315-v7 mAb YWMTWVRQAPGKGLEWVANIKQDGSEKY VH (aa) YVDSVKGRFTISRDNAKNSLYLQMNSLRAED TAVYYCARDLWFNDQAHYYGMDVWGQGT TVTVSS SARS-CoV-2 203 ARDLWFNDQAHYYGMDV S315-v7 mAb CDRH3 (aa) SARS-CoV-2 204 QVQLVQSGAEVKKPGASVKVSCKASGYPFT Heavy Chain SYGISWVRQAPGQGLEWMGWISTYNGNTNY IgHG1*01 Fd AQKFQGRVTMTTDTSTTTGYMELRRLRSDDT (aa) AVYYCARDYTRGAWFGESLIGGFDNWGQG TLVTVSSASTKGPSVFPLAPSSKSTSGGTAAL GCLVKDYFPEPVTVSWNSGALTSGVHTFPAV LQSSGLYSLSSVVTVPSSSLGTQTYICNVNHK PSNTKVDKRVEPKSC SARS-CoV-2 205 EIVLTQSPGTLSLSPGERATLSCRASQTVSSTS Light Chain LAWYQQKPGQAPRLLIYGASSRATGIPDRFSG IgKC*01 (aa) SGSGTDFTLTISRLEPEDFAVYYCQQHDTSLT FGGGTKVEIKRTVAAPSVFIFPPSDEQLKSGTA SVVCLLNNFYPREAKVQWKVDNALQSGNSQ ESVTEQDSKDSTYSLSSTLTLSKADYEKHKVY ACEVTHQGLSSPVTKSFNRGEC Linker (aa) 206 GSTSGSGKPGSGEGSTKG Linker (aa) 207 GSGKPGSGEG Linker (aa) 208 GKPGSGEG Linker (aa) 209 SGKPGSGE Linker (aa) 210 BPXXXZ, wherein each X is independently a glycine (G) or serine (S), B is a positively charged amino acid and Z is glycine (G) or a negatively charged amino acid Linker (aa) 211 (GxS)y, wherein x is 1-10 and y is 1-10 Linker (aa) 212 GGGGSGGGGSGGGGS Linker (aa) 213 GGGGSGGGGSGGGGSGGGGSGGGGS GGGGSGGGGSGGGGSGGGGSGGGGS Linker (aa) 214 GSTSGGGSGGGSGGGGSS Linker (aa) 215 EGKSSGSGSESKVD Linker (aa) 216 KESGSVSSEQLAQFRSLD Linker (aa) 217 GGGGS SARS-CoV-2 218 QVQLVQSGAEVKKPGASVKVSCKASGYPFT S309-scFab SYGISWVRQAPGQGLEWMGWISTYNGNTNY (H-L) (aa) AQKFQGRVTMTTDTSTTTGYMELRRLRSDDT AVYYCARDYTRGAWFGESLIGGFDNWGQG TLVTVSSASTKGPSVFPLAPSSKSTSGGTAAL GCLVKDYFPEPVTVSWNSGALTSGVHTFPAV LQSSGLYSLSSVVTVPSSSLGTQTYICNVNHK PSNTKVDKRVEPKSCGGGGSGGGGSGGGGS GGGGSGGGGSGGGGSGGGGSGGGGSGGGGS GGGGSEIVLTQSPGTLSLSPGERATLSCRASQ TVSSTSLAWYQQKPGQAPRLLIYGASSRATGI PDRFSGSGSGTDFTLTISRLEPEDFAVYYCQQ HDTSLTFGGGTKVEIKRTVAAPSVFIFPPSDE QLKSGTASVVCLLNNFYPREAKVQWKVDNA LQSGNSQESVTEQDSKDSTYSLSSTLTLSKAD YEKHKVYACEVTHQGLSSPVTKSFNRGEC SARS-CoV-2 219 EIVLTQSPGTLSLSPGERATLSCRASQTVSSTS S309-scFab LAWYQQKPGQAPRLLIYGASSRATGIPDRFSG (L-H) (aa) SGSGTDFTLTISRLEPEDFAVYYCQQHDTSLT FGGGTKVEIKRTVAAPSVFIFPPSDEQLKSGTA SVVCLLNNFYPREAKVQWKVDNALQSGNSQ ESVTEQDSKDSTYSLSSTLTLSKADYEKHKVY ACEVTHQGLSSPVTKSFNRGECGGGGSGGGG SGGGGSGGGGSGGGGSGGGGSGGGGSGGGG SGGGGSGGGGSQVQLVQSGAEVKKPGASVK VSCKASGYPFTSYGISWVRQAPGQGLEWMG WISTYNGNTNYAQKFQGRVTMTTDTSTTTG YMELRRLRSDDTAVYYCARDYTRGAWFGE SLIGGFDNWGQGTLVTVSSASTKGPSVFPLA PSSKSTSGGTAALGCLVKDYFPEPVTVSWNS GALTSGVHTFPAVLQSSGLYSLSSVVTVPSSS LGTQTYICNVNHKPSNTKVDKRVEPKSC SARS-CoV-2 220 QVQLVQSGAEVKKPGASVKVSCKASGYPFT S309-scFv SYGISWVRQAPGQGLEWMGWISTYNGNTNY (VH-VL) (aa) AQKFQGRVTMTTDTSTTTGYMELRRLRSDDT AVYYCARDYTRGAWFGESLIGGFDNWGQG TLVTVSSGGGGSGGGGSGGGGSEIVLTQSPGT LSLSPGERATLSCRASQTVSSTSLAWYQQKP GQAPRLLIYGASSRATGIPDRFSGSGSGTDFTL TISRLEPEDFAVYYCQQHDTSLTFGGGTKVEI K SARS-CoV-2 221 EIVLTQSPGTLSLSPGERATLSCRASQTVSSTS S309-scFv LAWYQQKPGQAPRLLIYGASSRATGIPDRFSG (VL-VH) (aa) SGSGTDFTLTISRLEPEDFAVYYCQQHDTSLT FGGGTKVEIKGGGGSGGGGSGGGGSQVQLV QSGAEVKKPGASVKVSCKASGYPFTSYGISW VRQAPGQGLEWMGWISTYNGNTNYAQKFQ GRVTMTTDTSTTTGYMELRRLRSDDTAVYY CARDYTRGAWFGESLIGGFDNWGQGTLVT VSS SARS-CoV-2 222 QVQLVQSGAEVKKPGASVKVSCKASGYPFT S309-scFv SYGISWVRQAPGQGLEWMGWISTYNGNTNY (VH-VL)- AQKFQGRVTMTTDTSTTTGYMELRRLRSDDT (VH-VL) (aa) AVYYCARDYTRGAWFGESLIGGFDNWGQG TLVTVSSGGGGSGGGGSGGGGSEIVLTQSPGT LSLSPGERATLSCRASQTVSSTSLAWYQQKP GQAPRLLIYGASSRATGIPDRFSGSGSGTDFTL TISRLEPEDFAVYYCQQHDTSLTFGGGTKVEI KGGGGSGGGGSGGGGSGGGGSQVQLVQSGA EVKKPGASVKVSCKASGYPFTSYGISWVRQA PGQGLEWMGWISTYNGNTNYAQKFQGRVT MTTDTSTTTGYMELRRLRSDDTAVYYCARD YTRGAWFGESLIGGFDNWGQGTLVTVSSGG GGSGGGGSGGGGSEIVLTQSPGTLSLSPGERA TLSCRASQTVSSTSLAWYQQKPGQAPRLLIY GASSRATGIPDRFSGSGSGTDFTLTISRLEPED FAVYYCQQHDTSLTFGGGTKVEIK SARS-CoV-2 223 QVQLVQSGAEVKKPGASVKVSCKASGYPFT S309-scFv- SYGISWVRQAPGQGLEWMGWISTYNGNTNY (VH-VL)- AQKFQGRVTMTTDTSTTTGYMELRRLRSDDT (VL-VH) (aa) AVYYCARDYTRGAWFGESLIGGFDNWGQG TLVTVSSGGGGSGGGGSGGGGSEIVLTQSPGT LSLSPGERATLSCRASQTVSSTSLAWYQQKP GQAPRLLIYGASSRATGIPDRFSGSGSGTDFTL TISRLEPEDFAVYYCQQHDTSLTFGGGTKVEI KGGGGSGGGGSGGGGSGGGGSEIVLTQSPGT LSLSPGERATLSCRASQTVSSTSLAWYQQKP GQAPRLLIYGASSRATGIPDRFSGSGSGTDFTL TISRLEPEDFAVYYCQQHDTSLTFGGGTKVEI KGGGGSGGGGSGGGGSQVQLVQSGAEVKKP GASVKVSCKASGYPFTSYGISWVRQAPGQGL EWMGWISTYNGNTNYAQKFQGRVTMTTDT STTTGYMELRRLRSDDTAVYYCARDYTRGA WFGESLIGGFDNWGQGTLVTVSS SARS-CoV-2 224 EIVLTQSPGTLSLSPGERATLSCRASQTVSSTS S309-scFv- LAWYQQKPGQAPRLLIYGASSRATGIPDRFSG (VL-VH)- SGSGTDFTLTISRLEPEDFAVYYCQQHDTSLT (VH-VL) (aa) FGGGTKVEIKGGGGSGGGGSGGGGSQVQLV QSGAEVKKPGASVKVSCKASGYPFTSYGISW VRQAPGQGLEWMGWISTYNGNTNYAQKFQ GRVTMTTDTSTTTGYMELRRLRSDDTAVYY CARDYTRGAWFGESLIGGFDNWGQGTLVT VSSGGGGSGGGGSGGGGSGGGGSQVQLVQS GAEVKKPGASVKVSCKASGYPFTSYGISWVR QAPGQGLEWMGWISTYNGNTNYAQKFQGR VTMTTDTSTTTGYMELRRLRSDDTAVYYCA RDYTRGAWFGESLIGGFDNWGQGTLVTVSS GGGGSGGGGSGGGGSEIVLTQSPGTLSLSPGE RATLSCRASQTVSSTSLAWYQQKPGQAPRLL IYGASSRATGIPDRFSGSGSGTDFTLTISRLEPE DFAVYYCQQHDTSLTFGGGTKVEIK SARS-CoV-2 225 EIVLTQSPGTLSLSPGERATLSCRASQTVSSTS S309-scFv- LAWYQQKPGQAPRLLIYGASSRATGIPDRFSG (VL-VH)- SGSGTDFTLTISRLEPEDFAVYYCQQHDTSLT (VL-VH) (aa) FGGGTKVEIKGGGGSGGGGSGGGGSQVQLV QSGAEVKKPGASVKVSCKASGYPFTSYGISW VRQAPGQGLEWMGWISTYNGNTNYAQKFQ GRVTMTTDTSTTTGYMELRRLRSDDTAVYY CARDYTRGAWFGESLIGGFDNWGQGTLVT VSSGGGGSGGGGSGGGGSGGGGSEIVLTQSP GTLSLSPGERATLSCRASQTVSSTSLAWYQQ KPGQAPRLLIYGASSRATGIPDRFSGSGSGTDF TLTISRLEPEDFAVYYCQQHDTSLTFGGGTK VEIKGGGGSGGGGSGGGGSQVQLVQSGAEV KKPGASVKVSCKASGYPFTSYGISWVRQAPG QGLEWMGWISTYNGNTNYAQKFQGRVTMT TDTSTTTGYMELRRLRSDDTAVYYCARDYT RGAWFGESLIGGFDNWGQGTLVTVSS SARS-CoV-2 226 QVQLVQSGAEVKKPGASVKVSCKASGYPFT S309-scFab- SYGISWVRQAPGQGLEWMGWISTYQGNTN (H-L) v1.1 YAQKFQGRVTMTTDTSTTTGYMELRRLRSD (aa) DTAVYYCARDYTRGAWFGESLIGGFDNWG QGTLVTVSSASTKGPSVFPLAPSSKSTSGGTA ALGCLVKDYFPEPVTVSWNSGALTSGVHTFP AVLQSSGLYSLSSVVTVPSSSLGTQTYICNVN HKPSNTKVDKRVEPKSCGGGGSGGGGSGGG GSGGGGSGGGGSGGGGSGGGGSGGGGSGGG GSGGGGSEIVLTQSPGTLSLSPGERATLSCRAS QTVSSTSLAWYQQKPGQAPRLLIYGASSRAT GIPDRFSGSGSGTDFTLTISRLEPEDFAVYYCQ QHDTSLTFGGGTKVEIKRTVAAPSVFIFPPSD EQLKSGTASVVCLLNNFYPREAKVQWKVDN ALQSGNSQESVTEQDSKDSTYSLSSTLTLSKA DYEKHKVYACEVTHQGLSSPVTKSFNRGEC SARS-CoV-2 227 EIVLTQSPGTLSLSPGERATLSCRASQTVSSTS S309-scFab- LAWYQQKPGQAPRLLIYGASSRATGIPDRFSG (L-H) v1.1 SGSGTDFTLTISRLEPEDFAVYYCQQHDTSLT (aa) FGGGTKVEIKRTVAAPSVFIFPPSDEQLKSGTA SVVCLLNNFYPREAKVQWKVDNALQSGNSQ ESVTEQDSKDSTYSLSSTLTLSKADYEKHKVY ACEVTHQGLSSPVTKSFNRGECGGGGSGGGG SGGGGSGGGGSGGGGSGGGGSGGGGSGGGG SGGGGSGGGGSQVQLVQSGAEVKKPGASVK VSCKASGYPFTSYGISWVRQAPGQGLEWMG WISTYQGNTNYAQKFQGRVTMTTDTSTTTG YMELRRLRSDDTAVYYCARDYTRGAWFGE SLIGGFDNWGQGTLVTVSSASTKGPSVFPLA PSSKSTSGGTAALGCLVKDYFPEPVTVSWNS GALTSGVHTFPAVLQSSGLYSLSSVVTVPSSS LGTQTYICNVNHKPSNTKVDKRVEPKSC SARS-CoV-2 228 QVQLVQSGAEVKKPGASVKVSCKASGYPFT S309-scFv- SYGISWVRQAPGQGLEWMGWISTYQGNTN (VH-VL) v1.1 YAQKFQGRVTMTTDTSTTTGYMELRRLRSD (aa) DTAVYYCARDYTRGAWFGESLIGGFDNWG QGTLVTVSSGGGGSGGGGSGGGGSEIVLTQS PGTLSLSPGERATLSCRASQTVSSTSLAWYQQ KPGQAPRLLIYGASSRATGIPDRFSGSGSGTDF TLTISRLEPEDFAVYYCQQHDTSLTFGGGTK VEIK SARS-CoV-2 229 EIVLTQSPGTLSLSPGERATLSCRASQTVSSTS S309-scFv- LAWYQQKPGQAPRLLIYGASSRATGIPDRFSG (VL-VH) v1.1 SGSGTDFTLTISRLEPEDFAVYYCQQHDTSLT (aa) FGGGTKVEIKGGGGSGGGGSGGGGSQVQLV QSGAEVKKPGASVKVSCKASGYPFTSYGISW VRQAPGQGLEWMGWISTYQGNTNYAQKFQ GRVTMTTDTSTTTGYMELRRLRSDDTAVYY CARDYTRGAWFGESLIGGFDNWGQGTLVT VSS SARS-CoV-2 230 QVQLVQSGAEVKKPGASVKVSCKASGYPFT S309-scFv- SYGISWVRQAPGQGLEWMGWISTYQGNTN (VH-VL)- YAQKFQGRVTMTTDTSTTTGYMELRRLRSD (VH-VL) v1.1 DTAVYYCARDYTRGAWFGESLIGGFDNWG (aa) QGTLVTVSSGGGGSGGGGSGGGGSEIVLTQS PGTLSLSPGERATLSCRASQTVSSTSLAWYQQ KPGQAPRLLIYGASSRATGIPDRFSGSGSGTDF TLTISRLEPEDFAVYYCQQHDTSLTFGGGTK VEIKGGGGSGGGGSGGGGSGGGGSQVQLVQ SGAEVKKPGASVKVSCKASGYPFTSYGISWV RQAPGQGLEWMGWISTYQGNTNYAQKFQG RVTMTTDTSTTTGYMELRRLRSDDTAVYYC ARDYTRGAWFGESLIGGFDNWGQGTLVTV SSGGGGSGGGGSGGGGSEIVLTQSPGTLSLSP GERATLSCRASQTVSSTSLAWYQQKPGQAPR LLIYGASSRATGIPDRFSGSGSGTDFTLTISRLE PEDFAVYYCQQHDTSLTFGGGTKVEIK SARS-CoV-2 231 QVQLVQSGAEVKKPGASVKVSCKASGYPFT S309-scFv- SYGISWVRQAPGQGLEWMGWISTYQGNTN (VH-VL)- YAQKFQGRVTMTTDTSTTTGYMELRRLRSD (VL-VH) v1.1 DTAVYYCARDYTRGAWFGESLIGGFDNWG (aa) QGTLVTVSSGGGGSGGGGSGGGGSEIVLTQS PGTLSLSPGERATLSCRASQTVSSTSLAWYQQ KPGQAPRLLIYGASSRATGIPDRFSGSGSGTDF TLTISRLEPEDFAVYYCQQHDTSLTFGGGTK VEIKGGGGSGGGGSGGGGSGGGGSEIVLTQS PGTLSLSPGERATLSCRASQTVSSTSLAWYQQ KPGQAPRLLIYGASSRATGIPDRFSGSGSGTDF TLTISRLEPEDFAVYYCQQHDTSLTFGGGTK VEIKGGGGSGGGGSGGGGSQVQLVQSGAEV KKPGASVKVSCKASGYPFTSYGISWVRQAPG QGLEWMGWISTYQGNTNYAQKFQGRVTMT TDTSTTTGYMELRRLRSDDTAVYYCARDYT RGAWFGESLIGGFDNWGQGTLVTVSS SARS-CoV-2 232 EIVLTQSPGTLSLSPGERATLSCRASQTVSSTS S309-scFv- LAWYQQKPGQAPRLLIYGASSRATGIPDRFSG (VL-VH)- SGSGTDFTLTISRLEPEDFAVYYCQQHDTSLT (VH-VL) v1.1 FGGGTKVEIKGGGGSGGGGSGGGGSQVQLV (aa) QSGAEVKKPGASVKVSCKASGYPFTSYGISW VRQAPGQGLEWMGWISTYQGNTNYAQKFQ GRVTMTTDTSTTTGYMELRRLRSDDTAVYY CARDYTRGAWFGESLIGGFDNWGQGTLVT VSSGGGGSGGGGSGGGGSGGGGSQVQLVQS GAEVKKPGASVKVSCKASGYPFTSYGISWVR QAPGQGLEWMGWISTYQGNTNYAQKFQGR VTMTTDTSTTTGYMELRRLRSDDTAVYYCA RDYTRGAWFGESLIGGFDNWGQGTLVTVSS GGGGSGGGGSGGGGSEIVLTQSPGTLSLSPGE RATLSCRASQTVSSTSLAWYQQKPGQAPRLL IYGASSRATGIPDRFSGSGSGTDFTLTISRLEPE DFAVYYCQQHDTSLTFGGGTKVEIK SARS-CoV-2 233 EIVLTQSPGTLSLSPGERATLSCRASQTVSSTS S309-scFv- LAWYQQKPGQAPRLLIYGASSRATGIPDRFSG (VL-VH)- SGSGTDFTLTISRLEPEDFAVYYCQQHDTSLT (VL-VH) v1.1 FGGGTKVEIKGGGGSGGGGSGGGGSQVQLV (aa) QSGAEVKKPGASVKVSCKASGYPFTSYGISW VRQAPGQGLEWMGWISTYQGNTNYAQKFQ GRVTMTTDTSTTTGYMELRRLRSDDTAVYY CARDYTRGAWFGESLIGGFDNWGQGTLVT VSSGGGGSGGGGSGGGGSGGGGSEIVLTQSP GTLSLSPGERATLSCRASQTVSSTSLAWYQQ KPGQAPRLLIYGASSRATGIPDRFSGSGSGTDF TLTISRLEPEDFAVYYCQQHDTSLTFGGGTK VEIKGGGGSGGGGSGGGGSQVQLVQSGAEV KKPGASVKVSCKASGYPFTSYGISWVRQAPG QGLEWMGWISTYQGNTNYAQKFQGRVTMT TDTSTTTGYMELRRLRSDDTAVYYCARDYT RGAWFGESLIGGFDNWGQGTLVTVSS SARS-CoV-2 234 DIVMTQSPDSLAVSLGERATINCKSSQSVLYS S300-v14 SNNKNYLAWYQQKPGQPPKLLISWASTRESG mAb VL VPDRFSGSGSGTDFTLTISSLQAEDVAVYYCQ (VK) (aa) QYYSAPGITFGQGTRLEIK SARS-CoV-2 235 QSVLYSSNNKNY S300-v14 mAb CDRL1 (aa) SARS-CoV-2 236 WAS S300-v14 mAb CDRL2 (aa) SARS-CoV-2 237 QQYYSAPGIT S300-v14 mAb CDRL3 (aa) SARS-CoV2 238 GACATCGTGATGACCCAGTCTCCAGACTCA S300-v14 CTGGCTGTGTCTCTGGGCGAGAGGGCCACC mAb VL ATCAACTGTAAGTCCAGCCAGAGTGTTTTA (VK) (nt) TACAGCTCCAACAATAAGAACTACTTAGC TTGGTACCAGCAGAAACCAGGACAGCCTCC TAAGCTGCTCATTTCCTGGGCTTCTACCCG GGAATCCGGGGTCCCTGACCGATTCAGTGG CAGCGGGTCTGGGACAGATTTCACTCTCAC CATCAGCAGCCTGCAGGCTGAAGATGTGGC AGTTTATTACTGTCAACAATATTATAGTGC TCCCGGGATCACCTTCGGCCAGGGGACAC GACTGGAGATTAAAC SARS-CoV2 239 QVQLQESGPGLVKPSETLSLTCTVSGGSVTSG S307 mAb SYYWSWIRQPPGKGLEWIGYMYYSGSTNYN VH (aa) PSLKSRVTISVDTSKNQFSLKLSSVTAADTAV YYCARAGCTGITCLRYDYYYGLDVWGQGT TVTVSS SARS-CoV2 240 GGSVTSGSYY S307 mAb CDRH1 (aa) SARS-CoV2 241 MYYSGST S307 mAb CDRH2 (aa) SARS-CoV2 242 ARAGCTGITCLRYDYYYGLDV S307 mAb CDRH3 (aa) SARS-CoV2 243 EIVLTQSPGTLSLSPGKRATLSCRASQSVSSSY S307 mAb LAWYQQRPGQAPRLLIYGASSRAAGIPDRFS VL(Vκ) (aa) GSGSGTDFTLTISRLEPEDFAVYYCQQYGSSS WTFGQGTKVEIK SARS-CoV2 244 QSVSSSY S307 mAb CDRL1 (aa) SARS-CoV2 245 GAS S307 mAb CDRL2 (aa) SARS-CoV2 246 QQYGSSSWT S307 mAb CDRL3 (aa) SARS-CoV2 247 CAGGTGCAGCTGCAGGAGTCGGGCCCAGG S307 mAb ACTGGTGAAGCCTTCGGAGACCCTGTCCCT VH (nt) CACCTGCACTGTCTCTGGTGGCTCCGTCAC CAGTGGTAGTTACTACTGGAGCTGGATCC GGCAGCCCCCAGGGAAGGGACTGGAGTGG ATTGGGTATATGTATTACAGTGGGAGCAC CAATTACAACCCCTCCCTCAAGAGTCGAGT CACCATATCAGTAGACACGTCCAAGAACCA GTTCTCCCTGAAGCTGAGCTCTGTGACCGCT GCGGACACGGCCGTGTATTACTGTGCGAG GGCAGGTTGTACTGGTATCACCTGCTTA CGTTACGACTACTACTACGGTCTGGACG TCTGGGGCCAAGGGACCACGGTCACCGTCT CCTCA SARS-CoV2 248 GAAATTGTGTTGACGCAGTCTCCAGGCACC S307 mAb CTGTCTTTGTCTCCAGGGAAAAGAGCCACC VL(Vκ) (nt) CTCTCCTGCAGGGCCAGTCAGAGTGTTAG CAGCAGCTACTTAGCCTGGTACCAGCAGA GACCTGGCCAGGCTCCCAGGCTCCTCATCT ATGGTGCATCCAGCAGGGCCGCTGGCATC CCAGACAGGTTCAGTGGCAGTGGGTCTGGG ACAGACTTCACTCTCACCATCAGCAGACTG GAGCCTGAAGATTTTGCAGTGTATTACTGT CAGCAGTATGGTAGCTCATCGTGGACGT TCGGCCAAGGGACCAAGGTGGAAATCAAA C SARS-CoV-2 249 CAGGTTCAGCTGGTGCAGTCTGGAGCTGAG S309-v1 mAb GTGAAGAAGCCTGGGGCCTCAGTGAAGGTC VH (nt) TCCTGCAAGGCTTCTGGTTACCCCTTTACC AGTTATGGTATCAGCTGGGTGCGACAGGC CCCTGGACAAGGGCTTGAGTGGATGGGATG GATCAGCACTTACAATGGTAACACAAATT ATGCACAGAAGTTCCAGGGCAGAGTCACCA TGACCACAGACACATCCACGACCACAGGCT ACATGGAGCTGAGGAGGCTGAGATCTGACG ACACGGCCGTGTATTACTGTGCGAGAGATT ATACTCGTGGTGCTTGGTTCGGGGAGTC ATTGATAGGGGGCTTTGACAACTGGGGCC AGGGAACCCTGGTCACCGTCTCCTCA SARS-CoV-2 250 GAAATTGTGTTGACGCAGTCTCCAGGCACC S309-v13 CTGTCTTTGTCTCCAGGGGAAAGAGCCACC mAb VL(VK) CTCTCCTGCAGGGCCAGTCAGACTGTTAGC (nt) AGCACCTCCTTAGCCTGGTACCAGCAGAAA CCTGGCCAGGCTCCCAGGCTCCTCATCTAT GGTGCATCCAGCAGGGCCACTGGCATCCCA GACAGGTTCAGCGGCAGTGGGTCTGGGACA GACTTCACTCTCACCATCAGCAGACTGGAG CCTGAAGATTTTGCAGTGTATTACTGTCAGC AGCATGATACCTCACTCACTTTCGGCGGAG GGACCAAGGTGGAGATCAAAC CMV 251 GACATTGATTATTGACTAGTTATTAATAGTA promoter (nt) ATCAATTACGGGGTCATTAGTTCATAGCCC ATATATGGAGTTCCGCGTTACATAACTTAC GGTAAATGGCCCGCCTGGCTGACCGCCCAA CGACCCCCGCCCATGACGTCAATAATGACG TATGTTCCCATAGTAACGCCAATAGGGACT TTCCATTGACGTCAATGGGTGGAGTATTTA CGGTAAACTGCCCACTTGGCAGTACATCAA GTGTATCATATGCCAAGTACGCCCCCTATT GACGTCAATGACGGTAAATGGCCCGCCTGG CATTATGCCCAGTACATGACCTTATGGGAC TTTCCTACTTGGCAGTACATCTACGTATTAG TCATCGCTATTACCATGGTGATGCGGTTTTG GCAGTACATCAATGGGCGTGGATAGCGGTT TGACTCACGGGGATTTCCAAGTCTCCACCC CATTGACGTCAATGGGAGTTTGTTTTGGCA CCAAAATCAACGGGACTTTCCAAAATGTCG TAACAACTCCGCCCCATTGACGCAAATGGG CGGTAGGCGTGTACGGTGGGAGGTCTATAT AAGCAGAGCTCGTTTAGTGAACCGTCAGAT CGCCTGGAGACGCCATCCACGCTGTTTTGA CCTCCATAGAAGACACCGGGACCGATCCAG CCTCCGCGGCCGGGAACGGTGCATTGGAAC GCGGATTCCCCGTGCCAAGAGTGACGTAAG TACCGCCTATAGAGTCTATAGGCCCACCCC CTTGGCTTCGTTAG Signal peptide 252 ATGGGATGGTCATGTATCATCCTTTTTCTAG (nt) TAGCAACTGCAACCGGTGT Poly- 253 AACTTGTTTATTGCAGCTTATAATGGTTACA adenylation AATAAAGCAATAGCATCACAAATTTCACAA signal ATAAAGCATTTTTTTCACTGCATTCTAGTTG sequence (nt) TGGTTTGTCCAAACTCATCAATGTATCTTAT CATGTCTGGATC SARS-CoV-2 254 GTACGGTGGCTGCACCATCTGTCTTCATCTT Light Chain CCCGCCATCTGATGAGCAGTTGAAATCTGG IgKC*01 (nt) AACTGCCTCTGTTGTGTGCCTGCTGAATAAC TTCTATCCCAGAGAGGCCAAAGTACAGTGG AAGGTGGATAACGCCCTCCAATCGGGTAAC TCCCAGGAGAGTGTCACAGAGCAGGACAG CAAGGACAGCACCTACAGCCTCAGCAGCAC CCTGACGCTGAGCAAAGCAGACTACGAGA AACACAAAGTCTACGCCTGCGAAGTCACCC ATCAGGGCCTGAGCTCGCCCGTCACAAAGA GCTTCAACAGGGGAGAGTGTTAG SARS-CoV-2 255 GCGTCGACCAAGGGCCCATCGGTCTTCCCC CH1-CH3 CTGGCACCCTCCTCCAAGAGCACCTCTGGG Glm17; GGCACAGCGGCCCTGGGCTGCCTGGTCAAG IgG1*01 (nt) GACTACTTCCCCGAACCTGTGACGGTCTCG TGGAACTCAGGCGCCCTGACCAGCGGCGTG CACACCTTCCCGGCTGTCCTACAGTCCTCAG GACTCTACTCCCTCAGCAGCGTGGTGACCG TGCCCTCCAGCAGCTTGGGCACCCAGACCT ACATCTGCAACGTGAATCACAAGCCCAGCA ACACCAAGGTGGACAAGAGAGTTGAGCCC AAATCTTGTGACAAAACTCACACATGCCCA CCGTGCCCAGCACCTGAACTCCTGGGGGGA CCGTCAGTCTTCCTCTTCCCCCCAAAACCCA AGGACACCCTCATGATCTCCCGGACCCCTG AGGTCACATGCGTGGTGGTGGACGTGAGCC ACGAAGACCCTGAGGTCAAGTTCAACTGGT ACGTGGACGGCGTGGAGGTGCATAATGCCA AGACAAAGCCGCGGGAGGAGCAGTACAAC AGCACGTACCGTGTGGTCAGCGTCCTCACC GTCCTGCACCAGGACTGGCTGAATGGCAAG GAGTACAAGTGCAAGGTCTCCAACAAAGCC CTCCCAGCCCCCATCGAGAAAACCATCTCC AAAGCCAAAGGGCAGCCCCGAGAACCACA GGTGTACACCCTGCCCCCATCCCGGGAGGA GATGACCAAGAACCAGGTCAGCCTGACCTG CCTGGTCAAAGGCTTCTATCCCAGCGACAT CGCCGTGGAGTGGGAGAGCAATGGGCAGC CGGAGAACAACTACAAGACCACGCCTCCCG TGCTGGACTCCGACGGCTCCTTCTTCCTCTA TAGCAAGCTCACCGTGGACAAGAGCAGGTG GCAGCAGGGGAACGTCTTCTCATGCTCCGT GATGCATGAGGCTCTGCACAACCACTACAC GCAGAAGAGCCTCTCCCTGTCCCCGGGTAA ATGA Signal peptide 256 MGWSCIILFLVATATG (aa) SARS-CoV-2 257 atgggctggtectgtatcatcctgttcctggtcgccacagccaccggagt S309-v1.1 gcacagccaagtgcagctggtccagagcggcgccgaggtgaagaag mAb CH1- cccggcgctagcgtgaaggtgtcctgtaaagccagcggatatcctttta CH3 G1m17; ccagctacggcatctectgggtgeggcaggccectggccagggcctg IgGHG1*01 gaatggatgggctggatcagcacctaccagggaaataccaactacgc LS; GAALIE; ccagaagttccagggaagagtgacaatgaccacagatacatctacaac signal peptide caccggctacatggaactgaggcggctgagaagcgacgacaccgcc (nt-CO) gtgtactactgcgccagagattacaccagaggcgcttggttcggcgag agcctgatcggcggcttcgacaactggggccagggaaccctggtgac agtgtctagcgcttctaccaaaggcccttctgtctttcctctggccccttct agcaagtctacaagcggaggcaccgccgccctgggctgcctggtgaa ggactacttccccgagcccgtgaccgtgagctggaatagcggcgccct gacaagcggcgtgcacaccttcccagctgtgctgcagagcagcggcc tgtatagcctgagcagcgtggtcaccgtgcccagcagcagcctggga acacagacctacatctgcaacgtgaaccacaagccttctaataccaagg tggataagaaggtggaacctaagagctgcgacaaaacacacacatgc cctccatgtectgctccagagctgctggccggccccagcgttffictgttc ccccccaaacctaaagacaccctgatgatcagcagaacccctgaggtg acctgtgtggtggtggacgtgtcccacgaagatcctgaggtgaagttca actggtacgtggatggagtggaagtgcacaacgccaagaccaaacct agagaagagcagtacaacagcacatatagagtcgtgtccgtgcttaca gtgctgcaccaggactggctgaatggaaaggaatacaagtgcaaggt gtccaacaaggccctgcctctgcctgaggagaagacaatctctaaagc caagggccaacctcgggaacctcaggtgtacacactgccccccagcc gggacgagctgaccaagaaccaggtgtccctgacctgcctggtcaag ggcttctacccctctgatatcgccgtggaatgggagagcaacggccaa cctgagaacaactacaagaccacccctccagtgctggacagcgacgg cagcttcttcctgtacagcaagctgaccgttgacaagtccagatggcag cagggcaacgtgttcagctgtagcgtcctgcacgaggccctgcattctc actacacccagaagagcctgtccctcagccctggcaagtga SARS-CoV-2 258 caagtgcagctggtccagagcggcgccgaggtgaagaagcccggcg S309-v1.1 ctagcgtgaaggtgtcctgtaaagccagcggatatccttttaccagctac mAb CH1- ggcatctcctgggtgcggcaggcccctggccagggcctggaatggat CH3 G1m17; gggctggatcagcacctaccagggaaataccaactacgcccagaagtt IgGHG1*01 ccagggaagagtgacaatgaccacagatacatctacaaccaccggct LS; GAALIE; acatggaactgaggcggctgagaagcgacgacaccgccgtgtactac (nt-CO) tgcgccagagattacaccagaggcgcttggttcggcgagagcctgatc ggcggcttcgacaactggggccagggaaccctggtgacagtgtctag cgcttctaccaaaggcccttctgtctttcctctggccccttctagcaagtct acaagcggaggcaccgccgccctgggctgcctggtgaaggactactt ccccgagcccgtgaccgtgagctggaatagcggcgccctgacaagc ggcgtgcacaccttcccagctgtgctgcagagcagcggcctgtatagc ctgagcagcgtggtcaccgtgcccagcagcagcctgggaacacaga cctacatctgcaacgtgaaccacaagccttctaataccaaggtggataa gaaggtggaacctaagagctgcgacaaaacacacacatgccctccat gtectgctccagagctgctggccggccccagcgifittctgttccccccc aaacctaaagacaccctgatgatcagcagaacccctgaggtgacctgt gtggtggtggacgtgtcccacgaagatcctgaggtgaagttcaactggt acgtggatggagtggaagtgcacaacgccaagaccaaacctagagaa gagcagtacaacagcacatatagagtcgtgtccgtgcttacagtgctgc accaggactggctgaatggaaaggaatacaagtgcaaggtgtccaac aaggccctgcctctgcctgaggagaagacaatctctaaagccaaggg ccaacctcgggaacctcaggtgtacacactgccccccagccgggacg agctgaccaagaaccaggtgtccctgacctgcctggtcaagggcttcta cccctctgatatcgccgtggaatgggagagcaacggccaacctgaga acaactacaagaccacccctccagtgctggacagcgacggcagcttct tcctgtacagcaagctgaccgttgacaagtccagatggcagcagggca acgtgttcagctgtagcgtcctgcacgaggccctgcattctcactacacc cagaagagcctgtccctcagccctggcaagtga SARS-CoV-2 259 atgggctggtectgtatcatcctgttcctggtcgccacagccaccggagt S309-v1.1 gcacagccaagtgcagctggtccagagcggcgccgaggtgaagaag mAb CH1- cccggcgctagcgtgaaggtgtcctgtaaagccagcggatatcctttta CH3 G1m17; ccagctacggcatctcctgggtgcggcaggcccctggccagggcctg IgGHG1*01 gaatggatgggctggatcagcacctaccagggaaataccaactacgc LS; signal ccagaagttccagggaagagtgacaatgaccacagatacatctacaac peptide (nt- caccggctacatggaactgaggcggctgagaagcgacgacaccgcc CO) gtgtactactgcgccagagattacaccagaggcgcttggttcggcgag agcctgatcggcggcttcgacaactggggccagggaaccctggtgac agtgtctagcgcttctaccaaaggcccttctgtctttcctctggccccttct agcaagtctacaagcggaggcaccgccgccctgggctgcctggtgaa ggactacttccccgagcccgtgaccgtgagctggaatagcggcgccct gacaagcggcgtgcacaccttcccagctgtgctgcagagcagcggcc tgtatagcctgagcagcgtggtcaccgtgcccagcagcagcctggga acacagacctacatctgcaacgtgaaccacaagccttctaataccaagg tggataagaaggtggaacctaagagctgcgacaaaacacacacatgc cctccatgtcctgctccagagctgctgggcggccccagcgtttttctgtt cccccccaaacctaaagacaccctgatgatcagcagaacccctgaggt gacctgtgtggtggtggacgtgtcccacgaagatcctgaggtgaagttc aactggtacgtggatggagtggaagtgcacaacgccaagaccaaacc tagagaagagcagtacaacagcacatatagagtcgtgtccgtgcttaca gtgctgcaccaggactggctgaatggaaaggaatacaagtgcaaggt gtccaacaaggccctgcctgcccctatcgagaagacaatctctaaagc caagggccaacctcgggaacctcaggtgtacacactgccccccagcc gggacgagctgaccaagaaccaggtgtccctgacctgcctggtcaag ggcttctacccctctgatatcgccgtggaatgggagagcaacggccaa cctgagaacaactacaagaccacccctccagtgctggacagcgacgg cagcttcttcctgtacagcaagctgaccgttgacaagtccagatggcag cagggcaacgtgttcagctgtagcgtcctgcacgaggccctgcattctc actacacccagaagagcctgtccctcagccctggcaagtga SARS-CoV-2 260 caagtgcagctggtccagagcggcgccgaggtgaagaagcccggcg S309-v1.1 ctagcgtgaaggtgtcctgtaaagccagcggatatccttttaccagctac mAb CH1- ggcatctcctgggtgcggcaggcccctggccagggcctggaatggat CH3 G1m17; gggctggatcagcacctaccagggaaataccaactacgcccagaagtt IgGHG1*01 ccagggaagagtgacaatgaccacagatacatctacaaccaccggct LS (nt-CO) acatggaactgaggcggctgagaagcgacgacaccgccgtgtactac tgcgccagagattacaccagaggcgcttggttcggcgagagcctgatc ggcggcttcgacaactggggccagggaaccctggtgacagtgtctag cgcttctaccaaaggcccttctgtctttcctctggccccttctagcaagtct acaagcggaggcaccgccgccctgggctgcctggtgaaggactactt ccccgagcccgtgaccgtgagctggaatagcggcgccctgacaagc ggcgtgcacaccttcccagctgtgctgcagagcagcggcctgtatagc ctgagcagcgtggtcaccgtgcccagcagcagcctgggaacacaga cctacatctgcaacgtgaaccacaagccttctaataccaaggtggataa gaaggtggaacctaagagctgcgacaaaacacacacatgccctccat gtcctgctccagagctgctgggcggccccagcgtttttctgttccccccc aaacctaaagacaccctgatgatcagcagaacccctgaggtgacctgt gtggtggtggacgtgtcccacgaagatcctgaggtgaagttcaactggt acgtggatggagtggaagtgcacaacgccaagaccaaacctagagaa gagcagtacaacagcacatatagagtcgtgtccgtgcttacagtgctgc accaggactggctgaatggaaaggaatacaagtgcaaggtgtccaac aaggccctgcctgcccctatcgagaagacaatctctaaagccaagggc caacctcgggaacctcaggtgtacacactgccccccagccgggacga gctgaccaagaaccaggtgtccctgacctgcctggtcaagggcttctac ccctctgatatcgccgtggaatgggagagcaacggccaacctgagaa caactacaagaccacccctccagtgctggacagcgacggcagcttctt cctgtacagcaagctgaccgttgacaagtccagatggcagcagggca acgtgttcagctgtagcgtcctgcacgaggccctgcattctcactacacc cagaagagcctgtccctcagccctggcaagtga S309-v13 261 tgggctggtcctgcatcatcctgttcctggtggccacagccaccggcgt Light chain gcacagcgagatcgtcctgacacagagccccggcacactgagcctct k1m3; ccccaggcgagcgggctacactgtcttgtagagcttctcagaccgtgtc IgKC*01; cagcaccagcctggcctggtatcagcagaaacctggccaggccccta signal peptide gactgctgatctacggcgccagcagcagagccaccggcatccctgat (nt-CO) agattcagcggcagcggatctggaaccgacttcaccctgaccatcagc cggctggaacccgaggactttgccgtgtactactgccagcaacacgac accagcctgaccttcggcggcggaacaaaggtggaaatcaagagaac cgtggccgcccctagcgtgttcatcttcccccccagcgacgagcagct gaagageggtacagatctgtggtgtgcctgctgaacaacttctacccg cgggaagccaaggtgcagtggaaggtggacaacgccctgcagagcg gcaacagccaggagagcgtgacagagcaggacagcaaggacagca cctacagcctgagcagcaccctgaccctgagcaaggccgactacgag aagcacaaggtgtacgcctgtgaagtgacccaccagggcctgtctagc cctgtgaccaagtcttttaacagaggcgagtgctga S309-v13 262 Gagatcgtcctgacacagagccccggcacactgagcctctccccagg Light chain cgagcgggctacactgtcttgtagagcttctcagaccgtgtccagcacc k1m3; agcctggcctggtatcagcagaaacctggccaggcccctagactgctg IgKC*01; (nt- atctacggcgccagcagcagagccaccggcatccctgatagattcagc CO) ggcagcggatctggaaccgacttcaccctgaccatcagccggctgga acccgaggactttgccgtgtactactgccagcaacacgacaccagcct gaccttcggcggcggaacaaaggtggaaatcaagagaaccgtggcc gcccctagcgtgttcatcttcccccccagcgacgagcagctgaagagc ggtacagcttctgtggtgtgcctgctgaacaacttctacccgcgggaag ccaaggtgcagtggaaggtggacaacgccctgcagagcggcaacag ccaggagagcgtgacagagcaggacagcaaggacagcacctacag cctgagcagcaccctgaccctgagcaaggccgactacgagaagcac aaggtgtacgcctgtgaagtgacccaccagggcctgtctagccctgtg accaagtcttttaacagaggcgagtgctga Signal peptide 263 Atgggctggtcctgcatcatcctgttcctggtggccacagccaccggc (nt-CO) gtgcacagc Signal peptide 264 MGWSCIILFLVATATGVHS (aa) SARS-CoV-2 265 ASTKGPSVFPLAPSSKSTSGGTAALGCLVKDY CH1-CH3 FPEPVTVSWNSGALTSGVHTFPAVLQSSGLYS G1m17; LSSVVTVPSSSLGTQTYICNVNHKPSNTKVDK IgG1*01 LS KVEPKSCDKTHTCPPCPAPELLGGPSVFLFPP no C-term Lys KPKDTLMISRTPEVTCVVVDVSHEDPEVKFN (aa) WYVDGVEVHNAKTKPREEQYNSTYRVVSVL TVLHQDWLNGKEYKCKVSNKALPAPIEKTIS KAKGQPREPQVYTLPPSRDELTKNQVSLTCL VKGFYPSDIAVEWESNGQPENNYKTTPPVLD SDGSFFLYSKLTVDKSRWQQGNVFSCSVLHE ALHSHYTQKSLSLSPG SARS-CoV-2 266 ASTKGPSVFPLAPSSKSTSGGTAALGCLVKDY CH1-CH3 FPEPVTVSWNSGALTSGVHTFPAVLQSSGLYS Glm17; LSSVVTVPSSSLGTQTYICNVNHKPSNTKVDK IgG1*01 LS KVEPKSCDKTHTCPPCPAPELLAGPSVFLFPP GAALIE no KPKDTLMISRTPEVTCVVVDVSHEDPEVKFN C-term Lys WYVDGVEVHNAKTKPREEQYNSTYRVVSVL (aa) TVLHQDWLNGKEYKCKVSNKALPLPEEKTIS KAKGQPREPQVYTLPPSRDELTKNQVSLTCL VKGFYPSDIAVEWESNGQPENNYKTTPPVLD SDGSFFLYSKLTVDKSRWQQGNVFSCSVLHE ALHSHYTQKSLSLSPG SARS-CoV-2 267 QVQLVQSGAEVKKPGASVKVSCKASGYPFT S309 VH SYGISWVRQAPGQGLEWMGX₁ ISTYX2X3NTN consensus YAQKFQGRVTMTTDTSTTTGYMELRRLRSD sequence DTAVYYCARDYTRGAX4FGESLIGGFDNWG QGTLVTVSS wherein X₁ = W, F, or Y; X₂ = N, Q, L, or T; X₃ = G, S, A, or Q; X₄ = W, F, or Y

EXAMPLES Example 1 Human Monoclonal Antibodies that Bind Spike Protein of SARS-CoV-2

B cells from a donor with previous SARS-CoV infection were sorted and immortalized with EBV and screened in 384-well plates (method described in European patent EP1597280B1, which method is incorporated herein by reference).

Two weeks after immortalization, supernatants of immortalized B cells were tested for antibody binding to SARS-CoV-2 Spike (“S”) protein using a flow cytometry-based method. Briefly, ExpiCHO cells were transfected with S protein of SARS-CoV-2 (strain BetaCoV/Wuhan-Hu-1/2019), or with an empty plasmid as a negative control. Fourteen monoclonal antibodies were identified that bind SARS-CoV-2 S, and were termed SARS-CoV-2 S300 through SARS-CoV-2 S312 and SARS-CoV-2 S315, respectively. Binding data for SARS-CoV-2 S300 through SARS-CoV-2 S310 are shown in FIGS. 4A and 4B (in these figures, the antibodies are identified as “S300”-“S310”, respectively). Graphs showing positive binding are indicated with boxes.

The heavy chain complementarity determining region (CDR)3 and light chain (L)CDR3 amino acid sequences of certain of these antibodies, along with the percent identity of the variable region gene sequences to germline (IMGT; imgt.org), are provided in Table 3.

TABLE 3 Blood sample VH (% HCDR3 VL (% LCDR3 SARS- SARS- mAb date identity) length HCDR3 sequence identity) sequence CoV CoV-2 Specificity S309 2013 VH1-18 20 ARDYTRGAWFGESLIGGFDN VK3-20 QQHDTSLT + + RBD (97.22) (SEQ ID NO.: 108) (97.52) (SEQ ID NO.: 171) S315 2013 VH3-7 17 ARDLWWNDQAHYYGMDV VL3-25 QSADSSGTV + + RBD (97.92) (SEQ ID NO.: 181) (97.57) (SEQ ID NO.: 185) S303 2013 VH3-23 17 ARERDDIFPMGLNAFDI VK1-5 QQYDTYSWT + + RBD (90.28) (SEQ ID NO.: 66) (97.49) (SEQ ID NO.: 70) S304 2013 VH3-13 14 ARGDSSGYYYYFDY VK1-39 QQSYVSPTYT + + RBD (97.89) (SEQ ID NO.: 82) (93.55) (SEQ ID NO.: 86) S306 2013 VH 1-18 16 ASDYDFSSGYYHSFDY VK3-11 QQRSNWPPGCS + + Non-RBD (95.49) (SEQ ID NO.: 90) (98.92) (SEQ ID NO.: 94) S310 2013 VH1-69 19 ATRTYDSSGYRPYYYGLDV VL2-23 CSYAGSDTVI + + Non-RBD (92.71) (SEQ ID NO.: 158) (97.57) (SEQ ID NO.: 162)

Example 2 Binding of Antibodies to RBD of SARS-CoV-2 Using Octet

Strepavidin biosensors (Pall ForteBio) were used to immobilize anti-Strep Tag II antibody at 3 ug/ml (clone 5A9F9, Biotin, LabForce AG, Muttenz CH), after a hydration step for 10 minutes with Kinetics Buffer (KB; 0.01% endotoxin-free BSA, 0.002{circumflex over ( )} Tween-20, 0.005% NaN3 in PBS). SARS-CoV-2 RBD with a Strep Tag II (produced in-house) was then loaded for 6 min at a concentration of 4 μg/ml in KB. Antibodies from B cell supernatant were allowed to associate for 1620 seconds (27 minutes). To observe dissociation, sensors were moved from the antibody solution into KB and antibody dissociation was monitored.

The “S303” mAb comprises the S303-v1 VH and VL amino acid sequences provided in Table 2 (SEQ ID NOs.:63 and 67, respectively). The “S309” mAb comprises the S309-v1 VH and S309-v13 VL amino acid sequences provided in Table 2 (SEQ ID NOs.: 105 and 168, respectively). The alleles encoding SEQ ID NOs.:109 and 147-150 from S309 B cell were determined to be non-productive; SEQ ID NO.:168 was the productive allele.

Comparison of the binding curves for S303 and S309 mAbs to SARS-CoV-2 RBD (FIGS. 1A and 1B) indicates that S303 has both a faster on-rate and a faster off-rate than S309, suggesting that S309 may bind to SARS-CoV-2 RBD with higher affinity.

Example 3 Assessing Binding of Antibodies to RBD of SARS-CoV-2 and SARS-CoV-1 Using Octet

Unless the context clearly indicates otherwise (e.g., that antibodies were present in B cell supernatant, or an antibody Fab fragment was used), antibodies of the present disclosure are described in this and the subsequent Examples as recombinantly expressed human IgG1, in some cases with amino acid mutations in the Fc, as described herein.

Binding affinity of three SARS-CoV/SARS-CoV-2 cross-reactive recombinant antibodies (S303 rIgG1, S304 rIgG1, S309 rIgG1) and two SARS-CoV-1 specific antibodies (S109 rIgG1, S230 rIgG1) was tested by biolayer interferometry (BLI) using Octet. Affinity was measured by immobilizing the antibody on sensors and dipping the sensors into wells containing different concentrations of RBD.

Kinetics of antibody binding to RBD were recorded during the association phase, after which the sensors were dipped into buffer without antibody to observe kinetics of antibody detaching from the RBD during the dissociation phase. Briefly, protein A biosensors (Pall ForteBio) were used to immobilize recombinant antibodies at 2.7 ug/ml for 1 minute, after a hydration step for 10 minutes with Kinetics Buffer (KB; 0.01% endotoxin-free BSA, 0.002{circumflex over ( )} Tween-20, 0.005% NaN3 in PBS). Association curves were recorded for 5 minutes by incubating the antibody-coated sensors with different concentrations of SARS-CoV-1 RBD (Sino Biological) or SARS-CoV-2 RBD (produced in house in Expi-CHO cells; residues 331-550 of spike from BetaCoV/Wuhan-Hu-1/2019, accession number MN908947). The highest RBD concentration tested was 10 ug/ml, then 1:2.5 serially diluted. Dissociation was recorded for 9 minutes by moving the sensors to wells containing KB. Affinities, represented by KD values, were calculated using a global fit model (Octet). Octet Red96 (ForteBio) equipment was used.

FIGS. 6A-6E show association and dissociation curves for antibodies using the highest RBD concentration tested (10m/m1). The switch from RBD solution to buffer is indicated with a vertical dashed line. Three cross-reactive antibodies (S303 rIgG1, S304 rIgG1 (VH of SEQ ID NO.:79, VL of SEQ ID NO.:73), S309 rIgG1 (VH of SEQ ID NO.:105, VL of SEQ ID NO.:168) and two SARS-CoV-1 specific antibodies (S230 and S109) were tested. All antibodies showed strong binding to SARS-CoV-1 RBD. S230 and S109 did not bind to SARS-CoV-2 RBD. Binding of S303 rIgG1, S304 rIgG1, and S309 rIGg1 to SARS-CoV-2 RBD was in the nanomolar to sub-picomolar range, with S309 rIgG1 showing the highest affinity. KD values are indicated below the graphs in FIGS. 6A-6E. KD values are estimates (KD=<1.0×10⁻¹²M) if the antibody binding is very strong and dissociation is slow. An exact KD for S309 rIgG1 could not be measured by this assay since the dissociation was too slow.

Example 4 Neutralization of SARS-CoV-2 Infection

Replication-incompetent viruses pseudotyped with the SARS-CoV-2 S gene (isolate BetaCoV/Wuhan-Hu-1/2019; accession number MN908947) were produced using methods as previously described (Temperton N J, et al. (2005) Longitudinally profiling neutralizing antibody response to SARS coronavirus with pseudotypes. Emerg Infect Dis 11(3):411-416). Briefly, HEK293T/17 cells were cotransfected with a SARS-CoV-2 S-expressing plasmid (phCMV1, Genlantis) and with a complementing viral-genome reporter gene vector, pNL4-3. Luc+.E-R+. A single-cycle infectivity assay was used to measure the neutralization of luciferase-encoding virions pseudotyped with the SARS-CoV-2 S protein, as previously described (Temperton N J, et al. (2007) A sensitive retroviral pseudotype assay for influenza H5N1-neutralizing antibodies. Influenza Other Respi Viruses 1(3):105-112.). Briefly, appropriate dilutions of the virion-containing culture supernatants were preincubated at 37° C. for 1 h with antibodies at various concentrations, and the virus-mAb mixtures were then added to Vero E6 cells that had been seeded the day before infection. The cells were then lysed with Steady-Glo reagent (Promega, E2520), and the relative luminescence units (RLU) in the cell lysates were determined on a luminometer microplate reader (Synergy H1 Hybrid Multi-Mode Reader; Biotek). The reduction of infectivity was determined by comparing the RLU in the presence and absence of antibody and expressed as percentage of neutralization.

Antibodies S300-v1 (VH: SEQ ID NO.:1; VL: SEQ ID NO.:5), S301, S302, 5303-v1 (VH SEQ ID NO.:63; VL SEQ ID NO.:67), S304 (VH SEQ ID NO.:79; VL SEQ ID NO.:83), S306 (VH SEQ ID NO.:87; VL SEQ ID NO.:91), S307 (VH SEQ ID NO.:239; VL SEQ ID NO.:243), S308-v1, S309 (comprising the S309-v1 VH sequence set forth in SEQ ID NO: 105 and the S309-v13 VL sequence set forth in SEQ ID NO: 168), and S310 were tested for neutralization function (Table 4, FIG. 2A). Antibodies SARS-CoV-2 S300-v1 and SARS-CoV-2 S309 neutralized SARS-CoV-2 infection (FIGS. 2A and 2B).

TABLE 4 Percent neutralization of infection by antibodies (titration series) Dilution S300 S301 S302 S303 S304 S306 S307 S308 S309 S310 2 93 −31 −47 6 −21 −19 36 −46 65 −4 6 94 10 6 5 25 15 5 19 11 −15 18 75 21 −16 2 −22 −9 2 32 −29 −15 54 −41 7 −60 12 7 6 32 16 14 −6

Additional neutralization assays were carried out using plasma from SARS CoV-1 survivors and antibodies SARS-CoV-2 S309, S311, S312, S303-v1 (rIgG1), S304 (rIgG1), S306 (rIgG1), S310 (rIgG1), and S315 (FIG. 3A-3I). FIG. 3A shows neutralizing activity of SARS-CoV donor plasma. FIGS. 3B-3D and 3I show neutralizing activity of supernatant from B cells producing S309, S311, S312, and S315, respectively. FIGS. 3E-3H show neutralizing activity of recombinant antibody at various concentrations. Using this assay, supernatant containing antibody S309, S311, S312, or S315 neutralizes SARS-CoV-2 infection.

Additional neutralization assays were carried out using antibodies S303, S304, S306, S309 (VH SEQ ID NO.:105; VL SEQ ID NO.:168), S310, and S315. FIG. 13 shows neutralizing activity of these antibodies at various concentrations against SARS-CoV-2 pseudotyped MLV. DBT cells stably transfected with ACE2 (DBT-ACE2) were used as target cells. FIG. 34 shows neutralizing activity against SARS-CoV-1 pseudotyped MLV by these antibodies at various concentrations. Additional neutralization data for S304, S309, S304+S309, S315, and S315+S309 are shown in FIGS. 36 and 37.

Example 5 Neutralization of SARS-CoV-2 Infection

Neutralizing activity of two SARS-CoV-1 and SARS-CoV-2 cross-neutralizing antibodies, S304 rIgG1 and S309 (VH: SEQ ID NO.:105; VL: SEQ ID NO.:168) rIgG1, against SARS-CoV-2 pseudotyped viruses (SARS-CoV-2pp) was assessed.

Murine leukemia virus (MLV) pseudotyped with SARS-CoV-2 Spike protein (SARS-CoV-2pp) was used. DBT cells stably transfected with ACE2 (DBT-ACE2) were used as target cells. SARS-CoV-2pp was activated with trypsin TPCK at 10 μg/ml. Activated SARS-CoV-2pp was added to a dilution series of antibodies (starting with 50 μg/ml final concentration per antibody, 3-fold dilution). Antibodies were tested at concentrations from 50 μg/ml to 0.02 μg/ml. For the combination of S304 rIgG1 and S309 rIgG1, starting concentrations were 50 μg/ml for each antibody, i.e. the total starting antibody concentration was 100 μg/ml. DBT-ACE2 cells were added to the antibody-virus mixtures and incubated for 48 hours. Luminescence was measured after aspirating cell culture supernatant and adding steady-GLO substrate (Promega).

In this assay, S309 rIgG1 exhibited a neutralization of infection IC50 of 0.37 μg/ml, and S304 rIgG1 exhibited an IC50 of approximately 17 μg/ml. A combination of these two antibodies exhibited an IC50 of 0.077 μg/ml. See FIG. 7 and Table 5.

TABLE 5 IC50 (μg/mL) of antibodies S309 S304 S304 + S309 IC50 0.3707 ~16.95 0.07704

Further neutralization assays were carried out using the same procedure for recombinant monoclonal antibodies S309 and S315, singly and in combination. In this assay, S309 exhibited an IC50 of 1.091 μg/ml, and S315 exhibited an IC50 of 25.1 μg/ml. The combination of both of these antibodies exhibited an IC50 of 0.3047 μg/ml. See FIG. 23 and Table 6.

TABLE 6 IC50 (μg/mL) of antibodies and antibody combination S309 + S315 S309 S315 IC50 0.3047 1.091 25.10

Example 6 Reactivity of Human Monoclonal Antibodies Against SARS-Cov and SARS-CoV-2

Reactivity of additional human mAbs “S311” and “S312” against the spike S1 subunit protein and the RBD of SARS-CoV and SARS-CoV-2 protein was assessed by enzyme-linked immunosorbent assay (ELISA).

96-well plates were coated with recombinant SARS-CoV-2 Spike S1 Subunit Protein (Sino Biological), SARS-CoV-2 RBD (Sino Biological or produced in house; residues 331-550 of spike from BetaCoV/Wuhan-Hu-1/2019, accession number MN908947), recombinant SARS-CoV Spike Si Subunit Protein (Sino Biological), or SARS-CoV RBD (Sino Biological).

Wells were washed and blocked with PBS+1% BSA for 1 hour at room temperature, and were then incubated with serially diluted mAbs for 1 hour at room temperature. Bound mAbs were detected by incubating alkaline phosphatase-conjugated goat anti-human IgG (Southern Biotechnology: 2040-04) for 1 hour at room temperature, and were developed by 1 mg/ml p-nitrophenylphosphate substrate in 0.1 M glycine buffer (pH 10.4) for 30 min at room temperature. Optical density (OD) values were measured at a wavelength of 405 nm in an ELISA reader (Powerwave 340/96 spectrophotometer, BioTek).

Results are shown in FIG. 5A (SARS-CoV-2 S311) and FIG. 5B (SARS-CoV-2 S312).

Further assays were performed to investigate reactivity of antibody variants engineered from S300, S305, or S307 to RBD of SARS-CoV-2 and SARS-CoV-1, using the same procedure described above in this Example. Results are shown in FIGS. 38A-38D. Antibody “S300 V4-rIgG1,” as shown in FIG. 38C, comprises a VH comprising the amino acid sequence of SEQ ID NO.:1 and a VL (Vκ) comprising the amino acid sequence of SEQ ID NO.:234. Antibody “S307 V3-rIgG1,” as shown in FIG. 38D, comprises a VH comprising the amino acid sequence of SEQ ID NO.: 239 and a VL(Vκ) comprising the amino acid sequence of SEQ ID NO.:243.

Example 7 Neutralization of SARS-CoV-2 Infection by S309 and S315

Neutralizing activity of recombinant antibodies S309 (VH: SEQ ID NO.:105; VL SEQ ID NO.:168) rIgG1-MLNS and S315 rIgG1-MLNS against SARS-CoV-2 pseudotyped viruses (SARS-CoV-2pp) was determined. These recombinant antibodies included M428L and N434S mutations in the Fc domain (see, e.g., Zalevsky et al., Nat. Biotechnol. 28(2):157-159 (2010); this combination of Fc mutations is also referred-to as “MLNS” or “LS” in the present disclosure, including in the drawings).

Murine leukemia virus (MLV) pseudotyped with SARS-CoV-2 Spike protein (SARS-CoV-2pp) was used. DBT cells stably transfected with ACE2 (DBT-ACE2) were used as target cells. SARS-CoV-2pp was activated with trypsin TPCK at 10 μg/ml. Activated SARS-CoV-2pp was added to a dilution series of the tested antibody. DBT-ACE2 cells were added to the antibody-virus mixtures and incubated for 48 hours. Luminescence was measured after aspirating cell culture supernatant and adding steady-GLO substrate (Promega). Luciferase signal of infected cells was used to calculate the percentage of neutralization relative to a no-antibody control.

S309 rIgG1 MLNS (“S309-rIgG1-LS” in FIG. 9) exhibited a neutralization of infection IC50 of approximately 3.9 nM, and S315 rIgG1 MLNS (“S315-rIgG1-LSv1” in FIG. 9) exhibited an IC50 of approximately 111.7 mM. See FIG. 9.

Neutralizing activity of S309-rFab was compared to that of full-length S309 rIgG1 MLNS (“S309-rIgG1-LS” in FIG. 10). Full-length S309 rIgG-LS exhibited an IC50 of 3.821 nM, while S309-rFab exhibited an IC50 of 3.532 nM. See FIG. 10.

Example 8 Reactivity of Antibodies Against RBD of SARS-CoV-1, RBD OF SARS-COV-2, and Ectodomains of Various Coronaviruses

Reactivity of monoclonal antibodies against the RBDs of SARS-CoV-1 and SARS-CoV-2 and the Spike proteins of SARS-CoV-1, SARS-CoV-2, OC43 coronavirus, and MERS coronavirus was studied by enzyme-linked immunosorbent assay (ELISA). 384-well shallow ELISA plates were coated with stabilized prefusion Spike protein trimer of SARS-CoV-1, SARS-CoV-2, OC43, or MERS at 1 μg/ml, or with SARS-CoV-2 RBD (produced in house; residues 331-550 of spike from BetaCoV/Wuhan-Hu-1/2019, accession number MN908947) at 10 μg/ml, or SARS-CoV-1 RBD (Sino Biological) at 1 μg/ml.

Wells were washed and blocked with PBS+1% BSA for 1 hour at room temperature, and were then incubated with serially diluted antibody for 1-2 hours at room temperature. Antibodies were tested at a concentration range of 5 to 0.00028 μg/ml. Plates were washed and bound antibodies were detected by incubating alkaline phosphatase-conjugated goat anti-human IgG (Southern Biotechnology: 2040-04) for 1 hour at room temperature followed by color development using 1 mg/ml p-nitrophenylphosphate substrate (Sigma-Aldrich 71768) in 0.1 M glycine buffer (pH 10.4) for 30 min at room temperature. The optical density (OD) values were measured at a wavelength of 405 nm in an ELISA reader (Powerwave 340/96 spectrophotometer, BioTek).

The ELISA assay results are shown in FIGS. 8A-8K and 18A-18J. Recombinant antibodies, some bearing MLNS Fc mutations, are indicated with rIgG1.

Example 9 Binding of Antibodies to Spike Protein of SARS-CoV-1 and SARS-COV-2

ExpiCHO cells were transfected with phCMV1-SARS-CoV-2-S, SARS-spike_pcDNA.3 (strain SARS), or empty phCMV1 using Expifectamine CHO Enhancer. Two days after transfection, cells were collected for immunostaining with antibody. An Alexa647-labelled secondary antibody anti-human IgG Fc was used for detection. Binding of monoclonal antibody to transfected cells was analyzed by flow cytometry using a ZE5 Cell Analyzer (Biorard) and FlowJo software (TreeStar). Positive binding was defined by differential staining of CoV-S transfectants versus mock transfectants. Antibody S309 (VH of SEQ ID NO.:105; VL of SEQ ID NO.:168) was tested by flow cytometry at 10 μg/ml for the ability to stain ExpiCHO cells expressing the S protein of SARS-CoV-1 or SARS-CoV-2. Stacked histograms of flow cytometry graphs show antibody dose-dependent binding by S309 to SARS-CoV-1 or SARS-CoV-2 S protein. Results are shown in FIG. 11.

Binding of monoclonal antibodies S303, S304, S306, S309, S310, S315, S110, S124, S230, and S109 (all expressed as rIgG1) to SARS-CoV-1 S protein and SARS-CoV-2 S protein was measured by flow cytometry. Results are shown in FIGS. 12A, 12B, 40A, and 40B. Eight of the tested antibodies exhibited EC50 values ranging between 1.4 ng/ml and 6,100 ng/ml for SARS-CoV-2 S protein binding and between 0.8 ng/ml and 254 ng/ml for SARS-CoV-1 S protein binding.

Further binding assays using the same procedure were carried out for S309 and four engineered variants of S309 bearing different mutations in VH (N55Q, W50F, W105F, or W50F+G56A+W105F). Results are shown in FIG. 27. EC50 values for each antibody tested in these assays are shown in Table 7; the numbers enclosed in parentheses in the “Antibody” column in Table 7 correspond to the figure key in FIG. 27.

TABLE 7 VH VL EC50 EC50 SEQ SEQ (ng/ml) - (ng/ml) - Antibody ID NO. ID NO. Exp. 1 Exp. 2 S309 WT (″11″) 105 168 23.1 11.5 5309 N55Q (″12″) 113 168 22.3 9.6 S309 W50F (″13″) 129 168 21.8 8.9 S309 W105F (″14″) 119 168 21.4 8.4 S309 W50E-G56A-W105F 172 168 18.8 7.8 (″15″)

Additional binding assays using the same procedure were carried out using antibodies S303, S304, S306, S309, S310, S315, and comparator antibodies S109, S110, S124, and S230. Results are shown in FIGS. 33A and 42A (binding to SARS-CoV-2 S protein), and 33B and 42B (binding to SARS-CoV-1 S protein). MFI: mean fluorescence intensity as measured by flow cytometry.

The same assay was performed using recombinant antibodies S300 and S307. Results for antibody S300-rIgG1, which comprises a VH comprising the amino acid sequence of SEQ ID NO.:1 and a VL (VK) comprising the amino acid sequence of SEQ ID NO.:234, are shown in FIG. 39A. Results for antibody S307-rIgG1, which comprises a VH comprising the amino acid sequence of SEQ ID NO.: 239 and a VL (VK) comprising the amino acid sequence of SEQ ID NO.:24, are shown in FIG. 39B.

Example 10 Binding of Antibodies S309, S303, S304, AND S315 to RBD of SARS-CoV-2 and SARS-CoV-1

Affinity of recombinant antibodies S309, S303, S304, and S315 for RBD of CoV-1 and CoV-2 was tested using biolayer interferometry (BLI; Octet). Briefly, His-tagged RBD of SARS-CoV-1 or SARS-CoV-2 was loaded at 3 μg/ml in kinetics buffer (KB) for 15 minutes onto anti-HIS (HIS2) biosensors (Molecular Devices, ForteBio). Association of full-length antibodies was performed in KB at 15 μg/ml for 5 minutes. Association of Fab fragments was performed in KB at 5 μg/mL for 5 minutes. Dissociation in KB was measured for 10 minutes. Affinities, represented by KD values, were calculated using a global fit model (Octet). Octet Red96 (ForteBio) equipment was used.

FIGS. 14A-14D show association and dissociation curves for S309, S303, S304, and S315, respectively. Each of these antibodies bound to SARS-CoV-2 and SARS-CoV-1 RBD with nanomolar to sub-picomolar affinity. FIGS. 20A and 20B show association and dissociation curves for S309 IgG and S309 Fab, respectively. In these figures, the switch from antibody (or Fab) solution to buffer is indicated with a vertical dashed line.

Example 11 Binding of S309 IGG and S309 FAB to SARS-CoV-2 S Protein Ectodomain Trimer and RBD

Affinity and avidity determination of IgG1 and Fab fragment: biotinylated RBD of SARS-CoV-2 (produced in-house; amino acid residues 331-550 of spike protein from BetaCoV/Wuhan-Hu-1/2019, accession number MN908947, biotinylated with EZ-Link NHS-PEG4-Biotin from ThermoFisher) and biotinylated SARS-CoV-2 2P S avi-tagged were loaded at 7.5 μg/ml in Kinetics Buffer (KB; 0.01% endotoxin-free BSA, 0.002% Tween-20, 0.005% NaN3 in PBS) for 8 minutes onto Streptavidin biosensors (Molecular Devices, ForteBio). Association of IgG1 and Fab with target was performed in KB at 100, 33, 11, 3.6, 1.2 nM for 5 minutes. Dissociation in KB was measured for 10 minutes. KD values were calculated using a 1:1 global fit model (Octet).

Results are shown in FIGS. 41A and 41B. In this assay, S309 IgG bound to the SARS-CoV-2 RBD and to the S ectodomain trimer with sub-picomolar and picomolar avidities, respectively. S309 Fab bound to both the SARS-CoV-2 RBD and the S ectodomain trimer with nanomolar to sub-nanomolar affinities.

Example 12 Competitive Binding of Antibodies to RBD of SARS-CoV-1 OR SARS-CoV-2

Competitive binding of pairs of monoclonal antibodies to SARS-CoV-1 RBD or SARS-CoV-2 RBD was measured to identify respective binding sites of the antibodies.

Strepavidin biosensors (Pall ForteBio) were used to immobilize anti-Strep Tag II antibody at 3 ug/ml (clone 5A9F9, Biotin, LabForce AG, Muttenz CH), after a hydration step for 10 min with Kinetics Buffer (KB; 0.01% endotoxin-free BSA, 0.002{circumflex over ( )} Tween-20, 0.005% NaN3 in PBS). Either SARS-CoV-1 or SARS-CoV-2 RBD with a Strep Tag II (produced in-house) was then loaded for 6 min at a concentration of 4 μg/ml in KB. The first antibody was allowed to associate for a period of time, and then the second antibody was allowed to associate for 7 minutes (420 seconds). FIG. 15A shows competition of antibody pairs for binding to the RBD of SARS-CoV-1. FIG. 15B shows competition of antibody pairs for binding to the RBD of SARS-CoV-2. The dashed vertical lines in FIGS. 15A and 15B indicate the switch from the first antibody, indicated on the left of the matrix, to the second antibody, indicated on top of the matrix. Using these and other data, four antigenic regions or sites (I-IV in FIGS. 15A and 15B) were identified.

Example 13 Interference with RBD:Human ACE2 Binding

The ability of antibodies to interfere with RBD binding to human ACE2 was measured. ACE2-His (Bio-Techne AG) was loaded for 30 minutes at 5 μg/ml in kinetics buffer (KB) onto anti-HIS (HIS2) biosensors (molecular Devices-ForteBio) SARS-CoV-1 RBD-rabbit Fc or SARS-CoV-2 RBD-mouse Fc (Sino Biological Europe GmbH) at 1 μg/ml was associated for 15 minutes, after a preincubation with or without antibody at 30 μg/ml for 30 minutes. Dissociation was monitored for 5 minutes. FIG. 16 shows data obtained using antibody S309 or S230. FIGS. 19A and 19B show data obtained using antibodies S304, S303, or S230 (FIG. 19A), or RBD and antibody S315 (FIG. 19B). The vertical dashed line in each of FIGS. 16, 19A, and 19B indicates the start of the loading of RBD with or without antibody.

Example 14 Effector Function of Antibodies

Natural killer (NK)-mediated antibody-dependent cell cytotoxicity (ADCC) can contribute to viral control by killing infected cells displaying viral protein on their surface. To investigate the ability of antibodies to leverage this function, ADCC was interrogated in vitro using human NK cells (isolated from fresh blood of healthy donors using the MACSxpress NK Isolation Kit (Miltenyi Biotec, Cat. Nr.: 130-098-185)) as effector cells and SARS-CoV-2 S-transfected ExpiCHO cells as target cells. Target cells were incubated with different amounts of antibody and after 10 minutes were incubated with primary human NK cells as effector cells at a target:effector ratio of 9:1. Antibody-dependent cell killing was measured using a LDH release assay (Cytotoxicity Detection Kit (LDH) (Roche; Cat. Nr.: 11644793001)) after 4 hours of incubation at 37° C.

Macrophage- or dendritic cell-mediated antibody-dependent cellular phagocytosis (ADCP) can also contribute to viral control by clearing infected cells and by potentially stimulating T cell response with viral antigen presentation. ADCP was tested using peripheral blood mononuclear cells as phagocytes and ExpiCHO transfected with SARS-CoV-2 S fluorescently labeled with PKH67 Fluorescent Cell Linker Kits (Sigma Aldrich, Cat. Nr.: MINI67) as target cells. Target cells were incubated with different amounts of antibody for 10 minutes, followed by incubation with human PBMCs isolated from healthy donors that were fluorescently labeled with Cell Trace Violet (Invitrogen, Cat. Nr.: C34557) at an effector:target ratio of 20:1. After an overnight incubation at 37° C., cells were stained with anti-human CD14-APC antibody (BD Pharmingen, Cat. Nr.: 561708, Clone M5E2) to stain phagocytic cells. Antibody-mediated phagocytosis was determined by flow cytometry, measuring the % of monocytes that were positive for PKH67 fluorescence.

Antibodies S309 (VH SEQ ID NO.:105; VL SEQ ID NO.:168), S304, S306, S315, S230, and the combination of S309 and S304, were tested.

FIG. 17A shows ADCC function of antibodies using primary NK effector cells and SARS-CoV-2 S-expressing ExpiCHO as target cells. Symbols show means±SD of duplicate measurements. FIG. 17B shows ADCP function of antibodies using PBMCs as phagocytic cells and PKF67-labelled SARS-CoV-2 S-expressing ExpiCHO as target cells. Symbols show means±SD of duplicate measurements.

Fc variants of S309 were tested for ADCC. S309-LS includes the M428L and N434S Fc mutations. S309-GRLR includes the G236R/L328R Fc mutation, which exhibits minimal binding to FcγRs. S309-LS-GAALIE includes the MLNS and GAALIE (G236A/A330L/I332E) Fc mutations. Results are shown in FIG. 45.

Antibodies S303, S304, S306, S309, S315, and the combination of S309 and S315 were assayed for ADCC and ADCP function. FIG. 24A shows ADCC of antibodies using primary NK effector cells and SARS-CoV- or SARS-CoV-2 S-expressing ExpiCHO as target cells. The graph in FIG. 24A shows the % killing determined for one representative donor homozygous for the high affinity FcγRIIIa (symbols show mean±SD). FIG. 24B shows area under the curve (AUC) for the responses of cells from donors homozygous for the high affinity FcγRIIIa variant 158V (VV), compared to cells from donors heterozygous for 158V (FV) or homozygous for the low affinity variant 158F (FF) (mean±SD). FIG. 25A shows ADCP using PBMCs as phagocytic cells and PKH67-labelled SARS-CoV-2 S-expressing ExpiCHO as target cells, for one representative donor. % ADCP indicates the percentage of monocytes positive for PKH67. FIG. 25B shows the area under the curve (AUC) for the responses from multiple donors.

Example 15 Reactivity of Antibodies to Cell Lysate of SARS-COV-2-Infected Cells

Reactivity of antibodies S304, S306, S309, and S310 against cell lysate of SARS-CoV-2-infected VeroE6 cells was measured. FIG. 21A shows reactivity of the antibodies, as measured by indirect ELISA S against TX100-extracted lysate of SARS-CoV-2-infected VeroE6 cells. FIG. 21B shows reactivity of the antibodies, as measured by indirect ELISA S against SDS extracted (denatured) lysate of SARS-CoV-2-infected VeroE6 cells. FIG. 21C shows reactivity of human SARS-CoV-1 convalescent serum, as measured by indirect ELISA S against TX100-extracted or SDS-extracted lysate of SARS-CoV-2-infected VeroE6 cells.

Example 16 Neutralization of SARS-CoV-2 Infection by Antibodies S304 and S309, Alone or in Combination

Neutralization of SARS-CoV-2 infection by monoclonal antibodies S304 and S309 was assessed using a SARS-CoV-2 live virus assay. The live virus neutralization assay quantifies the number of infected cells by staining for viral nucleoprotein (NP) with an NP-specific polyclonal rabbit serum. Inhibition was assessed by measuring NP expression at 24 and 45 hours post infection. Enzyme immunoassay (EIA) was used to quantify the level of infection for each antibody dilution tested.

Data are shown in FIGS. 22A-22D. Neutralization was carried out for one hour at room temperature at the indicated antibody concentrations using Vero E6 cells in monolayer in 96-well plates. Wells were infected with 100 TCID50 of virus. After 24 or 45 hours, monolayers were fixed and stained for inhibition of NP expression. When combined, S304 and S309 show a synergistic enhancement of neutralization.

Example 17 Production of S309 RIGG Variant Antibodies

Recombinant IgG1 antibodies were produced using the VH and VL sequences of antibody S309. In this example, antibodies are referred-to as “S309-11”, “S309-12”, “S309-13”, “S309-14”, and “S309-15”, respectively.

“S309-11” comprises the wild-type VH sequence (SEQ ID NO: 105) and the wild-type VL sequence (SEQ ID NO: 168) of S309. “S309-12” comprises an N55Q mutation in CDRH2, providing a VH variant sequence (SEQ ID NO: 113) and the wild-type VL sequence (SEQ ID NO: 168) of S309. “S309-13” comprises a W50F mutation in VH (SEQ ID NO: 129) and the wild-type VL sequence (SEQ ID NO: 168) of S309. “S309-14” comprises a W105F VH variant sequence (SEQ ID NO: 119) and the wild-type VL sequence (SEQ ID NO: 168) of S309. “S309-15” comprises a W50F/G56A/W105F VH variant (SEQ ID NO: 172) and the wild-type VL sequence of S309 (SEQ ID NO: 168). S309 recombinant antibody (S309-11) and each of the four variants S309-12-S309-15 were produced by transient transfection and expression of a plasmid vector encoding the recombinant antibody in HD 293F cells (GenScript). A plasmid vector encoding the S309 antibodies also encoded a signal peptide as set forth in SEQ ID NO.:252. This signal peptide provided superior antibody production as compared to other signal peptides tested. Data not shown. Cells were harvested on day 4 and IgG expression was validated by Western blot and protein A titer analysis.

Example 18

BINDING OF S309 RIGG AND VARIANTS TO SARS-CoV-2 RBD

Binding of recombinant monoclonal antibody S309 and the four S309 variants described in Example 17 (S309-12-S309-15) to RBD was measured using surface plasmon resonance (SPR). SPR experiments were carried out with a Biacore T200 instrument using a single-cycle kinetics approach. Antibody expressed as IgG was captured on the surface and increasing concentrations of purified SARS-CoV-2 RBD, either glycosylated or deglycosylated form, were injected. SPR was conducted using a sensor chip with anti-human Fc covalently immobilized (GE). Buffer used was 10 mM HEPES pH 7.4, 150 mM NaCl, 3 mM EDTA, and 0.05% P20 detergent. Assays were conducted at 25° C. Recombinant antibodies were diluted from supernatant to approximately 2 μg/ml. RBD concentrations were 0.8 nM, 3.1 nM, 12.5 nM, 50 nM, and 200 nM. Glycosylated RBD was obtained by expression in HEK293 cells and purified using one-step Ni affinity purification. Deglycosylated RBD was obtained by expression in-house in Expi293 cells grown in the presence of kifunensine, purification using one-step Ni affinity purification, and treatment with endoglycosidase H. Single-cycle kinetics assays were carried out with 3 minute injections and 20 minute dissociation periods. Association and dissociation kinetics were monitored and fit to a binding model to determine affinity. Results are shown in FIGS. 30A-30F and Table 8.

TABLE 8 mAb Supernatant Glycosylated RBD Deglycosylated RBD S309 WT or K_(a) K_(d) K_(a) K_(d) variant K_(D) (1/Ms) (1/s) K_(D) (1/Ms) (1/s) S309−11 0.50 nM 10.0e4 5.0e−5 0.91 nM 3.0e5 2.8e−4 (WT) S309-11 0.68 nM  9.5e4 6.5e−5 0.98 nM 2.9e5 2.9e−4 (WT) replicate S309-12 0.46 nM  9.2e4 4.2e−5  1.3 nM 2.7e5 3.6e−4 (N55Q) S309-13 0.51 nM  9.9e4 5.0e−5  1.8 nM 3.0e5 5.3e−4 (W50F) S309-14 0.38 nM  1.0e5 3.9e−5  7.9 nM 9.8e5 7.7e−3 (W105F) S309-15  1.7 nM  9.9e4 1.6e−4 >10 nM estimated Kd (W50F/ with G56A/ steady-state fit W105F)

Binding to deglycosylated RBD was measured in two different SPR assays using different parameters. Experiment 1 used 10-minute injections and an RBD concentration series of 4-fold dilutions from 100 nM. Experiment 2 used 3-minute injections and a concentration series of 4-fold dilutions from 200 nM, as described above. Results are shown in Table 9. Results of Experiment 1 for S309-15 are also shown in FIG. 30F, top two panels.

TABLE 9 mAb Supernatant Experiment 1 Experiment 2 S309 WT or K_(a) K_(d) K_(a) K_(d) variant K_(D) (1/Ms) (1/s) K_(D) (1/Ms) (1/s) S309-11 (WT) 0.83 nM 3.0e5 2.5e−4 0.91 nM 3.0e5 2.8e−4 S309-11 (WT) 0.91 nM 3.0e5 2.7e−4 0.98 nM 2.9e5 2.9e−4 replicate S309-12 (N55Q) 1.2 nM 2.7e5 3.2e−4 1.3 nM 2.7e5 3.6e−4 S309-13 (W50F) 1.7 nM 2.8e5 4.6e−4 1.8 nM 3.0e5 5.3e−4 S309-14 14 nM Fit to steady 7.9 nM 9.8e5 7.7e−3 (W105F) state S309-15 37 nM Fit to steady Steady-state fit (W50F/G56A/W state not possible 105F)

Binding of recombinant antibody S309 and the four engineered variants to RBD was measured by surface plasmon resonance (SPR) using the same procedure described above, except using purified recombinant antibodies rather than cell culture supernatant. Results are shown in Table 10.

TABLE 10 Glycosylated RBD Deglycosylated RBD S309 WT or K_(a) K_(d) K_(a) K_(d) variant VH K_(D) (1/Ms) (1/s) K_(D) (1/Ms) (1/s) S309-11 (WT) 0.26 nM 9.3e4 2.4e−5 0.67 nM 3.4e5 2.3e−4 S309-12 (N55Q) 0.39 nM 8.5e4 3.3e−5 1.1 nM 3.1e5 3.2e−4 S309-13 (W50F) 0.39 nM 9.2e4 3.6e−5 1.4 nM 3.5e5 4.9e−4 S309-14 0.35 nM 9.6e5 3.4e−5 5.1 nM 1.5e6 7.9e−3 (W105F) S309-15 1.6 nM 9.4e4 1.5e−4 >10 nM estimate (W50F/G56A/ Kd with W105F) steady-state fit S309 G56A 0.54 nM 9.3e4 5.1e−5 0.70 nM 3.4e5 2.4e−4

Example 19 Neutralization of SARS-CoV-2 Infection by S309 Antibodies

Neutralizing activity of S309 and the four engineered S309 variants described in Examples 17 and 18 (“S309-12”-“S309-15”) was determined using a VSV-based luciferase reporter pseudotyping system (Kerafast). VSV pseudoparticles and antibody were mixed in DMEM and allowed to incubate for 30 minutes at 37° C. The infection mixture was then allowed to incubate with Vero E6 cells for 1h at 37° C., followed by the addition of DMEM with Pen-Strep and 10% FBS (infection mixture is not removed). The cells were incubated at 37° C. for 18-24 hours. Luciferase was measured using an Ensight Plate Reader (Perkin Elmer) after the addition of Bio-Glo reagent (Promega). Results are shown in FIG. 28. In FIG. 28, Variants-11-15 correspond to S309-11-S309-15, respectively. Calculated EC50 values based on this experiment are shown in Table 11.

TABLE 11 Antibody EC50 (ng/ml) S309-11 (WT VH) 109 S309-12 (N55Q VH) 103 S309-13 (W5OF VH) 97 S309-14 (W105F VH) 65 S309-15 (W50F/G56A/ 53 W105FVH)

Example 20 Antibody-Dependent Activation of Human FCFRIIIA or FCFRIIA

Antibody-dependent activation of human FcγRIIIa or FcγRIIa was examined. ExpiCHO cells were transiently transfected with SARS-CoV-2 S (BetaCoV/Wuhan-Hu-1/2019), and incubated with titrated concentrations of antibody for 10 minutes. ExpiCHO cells were then incubated with Jurkat cells expressing FcγRIIIa or FcγRIIa on their surface and stably transfected with NFAT-driven luciferase gene (Promega, Cat. Nr.: G9798 and G7018) at an effector to target ratio of 6:1 for FcγRIIIa and 5:1 for FcγRIIa. Activation of human FcγRs in this bioassay results in the NFAT-mediated expression of the luciferase reporter gene. Luminescence was measured after 21 hours of incubation at 37° C. with 5% CO₂, using the Bio-Glo-™ Luciferase Assay Reagent according to the manufacturer's instructions. Antibodies S303, S304, S306, S309, S315, and a combination of S309 and S315 were assayed, along with comparator antibody S230. Results are shown in FIGS. 31 and 32.

Example 21 Analysis of SARS-CoV-2 S Glycoprotein Sequences

Analysis of the S glycoprotein sequences of 2,229 SARS-CoV-2 isolates indicated that several mutations have occurred with variable frequency on the SARS-CoV-2 S ectodomain. FIG. 35A shows Spike protein variants occurring with a frequency of n>1 as spheres mapped onto the closed and open form of the full trimeric Spike ectodomain. The RBD and other Spike protein domains are shown as indicated. 40 mutations (out of 2229 total) are shown. Due to lack of detail in the PDB structures, only residue 367 (n=8) is highlighted in the RBD, and residues 476 (n=7) and 483 (n=17) are not. FIG. 35B shows the prevalence of variants in Spike glycoprotein by amino acid. Each dot is a distinct variant. The locations of Domain A and RBD are shown. Variants passing a frequency threshold of 0.1% are as indicated.

Further analysis of the S glycoprotein sequences was carried out using 11,839 SARS-CoV-2 isolates. FIG. 43 shows variants supported by at least two sequences (prevalence greater than 0.01%) rendered as indicated spheres mapped onto the closed (left) and open (right) form of the full trimeric Spike ectodomain. Each dot is a distinct variant. FIG. 43 shows Spike protein variants supported by at least two sequences as indicated spheres mapped onto the closed (left) and open (right) form of the full trimeric Spike ectodomain. The RBD and other Spike protein domains are shown in the colors indicated. 171 variants (out of 11,839 total Spike protein sequences analyzed) are shown. Variants are labeled if their prevalence is greater than 1% (D614G only) or if they are located within the RBD. The location of conserved N343 is also indicated.

Example 22 Competition of Antibody S309 with Antibodies Isolated from SARS-COV-2 Patients

Human monoclonal antibodies isolated from patients who recovered from SARS-CoV-2 infection were tested for overlapping RBD binding sites with antibody S309 (VH: SEQ ID NO:105; VL: SEQ ID NO.:113). Competition assays were performed using Octet (instrument: Octet Red96, ForteBio). Anti-His sensors (BIOSENSOR ANTI-PENTA-HIS (HIS1K)1*1ST) were used to immobilize in house produced His-tagged RBD of SARS-CoV-2 (residues 331-550 of Spike protein from BetaCoV/Wuhan-Hu-1/2019, accession number MN908947) at a concentration of 3 μg/ml. Antibodies were associated for 6 min at 15 μg/ml. All proteins were diluted in kinetics buffer (KB). Competing antibodies were then associated at the same concentration for additional 6 mins. Two antibodies were shown to compete with S309 for binding to RBD but, unlike S309, they were not neutralizing for SARS-CoV-2. Data not shown.

Example 23 Resistance Selection of SARS-COV-2 Against Monoclonal Antibody S309-12-MLNS

To examine resistance selection, SARS CoV-2 was passaged for over one month in the presence of Vero E6 cells and fixed concentrations of antibody S309 N55Q MLNS GAALIE (VH of SEQ ID NO.:113 and VL of SEQ ID NO.:168, with G236A, A330L, I332E, M428L, and N434S mutations in the Fc). The experimental scheme is illustrated in FIG. 44A. The details of infection and continuous viral culturing are summarized in FIG. 44B. Cytopathogenic effect (CPE) was evaluated by visual inspection of plates. Even when no CPE was observed, viral titers were evaluated by focus-forming assay with a methylcellulose overlay. Results are shown in FIG. 44C. No evidence of viral breakthrough in antibody-treated wells was observed, even at the minimum antibody concentration tested. Data are representative of wells in triplicate.

Example 24 Neutralization of SARS-CoV-2 Infection of CALU-3 Human Lung Cells by Antibody S309

Antibody S309 N55Q MLNS (VH of SEQ ID NO.:113 and VL of SEQ ID NO.:168, with M428L and N434S mutations in the Fc) was tested for its ability to neutralize live SARS-CoV-2 infection of Calu-3 human lung cells (which are positive for the transmembrane protease TMPRSS2) and VeroE6 cells using a nano luciferase assay. Results, including calculated IC50 values, are shown in FIG. 46.

Example 25 Neutralization of SARS-CoV-2 Infection by Antibody S309

Antibody S309 was tested for its ability to neutralize live SARS-CoV-2 virus infection using a nano luciferase assay and a IFA assay. Briefly, Vero E6 cells were infected with live SARS-CoV-2 luciferase virus for six hours. Data were collected using three different antibody concentrations: 1, 0.1, and 0.01 MOI. Results from the nano luciferase assay are shown in FIG. 47. Results from the IFA assay are shown in FIG. 48A (representative wells counted in the IFA) and 48B (quantified data using Cytation 5). Calculated IC50 values for each MOI are shown in the boxes below the graph in FIGS. 47 and 48B. Notably, no clusters of infection (or foci) were observed in this infection format.

Example 26 Neutralization of Live SARS-CoV-2 Infection by Antibodies S309 N55Q MLNS and S309 N55Q MLNS GAALIE

Antibodies S309 N55Q MLNS (also referred to herein as S309 N55Q LS, comprising M428L/N434S Fc mutations) and S309 N55Q MLNS GAALIE (also referred to herein as S309 N55Q LS GAALIE, comprising G236A, A330L, I332E, M428L, and N434S Fc mutations) were assayed for the ability to neutralize live SARS-CoV-2 virus infection. Each of S309 N55Q MLNS and S309 N55Q MLNS GAALIE comprises a VH having the sequence set forth in SEQ ID NO.: 113 and a VL having the sequence set forth in SEQ ID NO.: 168. Results are shown in FIG. 49. The calculated EC50 for S309 N55Q MLNS was 100.1 ng/ml. The calculated EC50 for S309 N55Q MLNS GAALIE was 78.3 ng/ml.

Example 27 Neutralization of SARS-CoV-2 Pseudotyped Virus by Antibodies S309 N55Q MLNS and S309 N55Q MLNS GAALIE

Neutralization of SARS-CoV-2 pseudotyped virus by antibodies S309 N55Q MLNS (also referred to herein as S309 N55Q LS) and S309 N55Q MLNS GAALIE (also referred to herein as S309 N55Q MLNS GAALIE) was tested. Each of S309 N55Q MLNS and S309 N55Q MLNS GAALIE comprises a VH having the sequence set forth in SEQ ID NO.: 113 and a VL having the sequence set forth in SEQ ID NO.: 168. The pseudotyped virus was VSV pseudotyped with SARS-CoV-2 Spike protein. Results are shown in FIG. 50A (S309 N55Q MLNS) and FIG. 50B (S309 N55Q MLNS GAALIE). The calculated EC50 value for S309 N55Q MLNS was 24.06 ng/ml. The calculated EC50 value for S309 N55Q MLNS GAALIE was 22.09 ng/ml.

Example 28 Binding of Antibodies S309 N55Q MLNS and S309 N55Q MLNS GAALIE to SARS-CoV-2 RBD

Binding of antibodies S309 N55Q MLNS and S309 N55Q MLNS GAALIE to SARS-CoV-2 RBD was measured by surface plasmon resonance (SPR). Each of S309 N55Q MLNS and S309 N55Q MLNS GAALIE comprises a VH having the sequence set forth in SEQ ID NO.: 113 and a VL having the sequence set forth in SEQ ID NO.: 168. Results are shown in FIG. 51A (S309 N55Q MLNS) and FIG. 51B (S309 N55Q MLNS GAALIE).

Example 29 Binding of Antibodies S309 N55Q MLNS and S309 N55Q MLNS GAALIE to SARS-CoV-2 Spike Protein

Binding of antibodies S309 N55Q MLNS (also referred to herein as S309 N55Q LS) and S309 N55Q MLNS GAALIE (also referred to herein as S309 N55Q LS GAALIE) to SARS-CoV-2 to SARS-CoV-2 Spike protein was measured by flow cytometry. Each of S309 N55Q MLNS and S309 N55Q MLNS GAALIE comprises a VH having the sequence set forth in SEQ ID NO.: 113 and a VL having the sequence set forth in SEQ ID NO.: 168. Results are shown in FIG. 52A (S309 N55Q MLNS) and FIG. 52B (S309 N55Q MLNS GAALIE). Data are expressed as the percentage of cells identified as positive for antibody binding.

Example 30 Binding of Antibodies S309 N55Q MLNS AND S309 N55Q MLNS GAALIE to Human FCF Receptors

Binding of antibodies S309 N55Q MLNS and S309 N55Q MLNS GAALIE to human Fcγ receptors was assayed using SPR. Binding to FcγRIIa (both low affinity R131 and high affinity H131 alleles), FcγRIIIa (both low affinity F158 and high affinity V158 alleles), and FCyRIIb was measured. Each of S309 N55Q MLNS and S309 N55Q MLNS GAALIE comprises a VH having the sequence set forth in SEQ ID NO.: 113 and a VL having the sequence set forth in SEQ ID NO.: 168.

Biotin CAPture Reagent (modified streptavidin) was injected across all flow cells of a CAP sensor chip docked in a Biacore T200 (Cytiva). Biotinylated Fc receptors at 1 μg/mL were injected across a single flow cell at 10 μL/min for 60 seconds (one receptor per flow cell), with one flow cell reserved as a reference surface. Antibody at 100 μg/mL (diluted in HBS-EP+) was injected across all flow cells for 200 seconds using a flow rate of 30 μL/min and association was monitored. Dissociation was monitored for another 200 seconds after injection. Data was collected at 10 Hz. After each binding measurement, CAP Regeneration reagent was injected to prepare the surface for a new cycle. Experiments were performed at 25° C., with the samples held at 15° C. in the instrument prior to injection. Results are shown in FIG. 53 (wherein the MLNS mutation is indicated as “LS” in the figure key).

Example 31 Binding of Antibodies S309 MLNS, S309 N55Q MLNS, and S309 N55Q MLNS GAALIE to Complement Component C1Q

Binding of antibodies S309 MLNS (also referred to herein as S309 LS), S309 N55Q MLNS (also referred to herein as S309 N55Q LS), and S309 N55Q MLNS GAALIE (also referred to herein as S309 N55Q LS GAALIE) to complement component C1q was measured by biolayer interferometry (BLI) on an Octet instrument. S309 MLNS comprises a VH having the sequence set forth in SEQ ID NO.:105 and a VL having the sequence set forth in SEQ ID NO.:168. Each of S309 N55Q MLNS and S309 N55Q MLNS GAALIE comprises a VH having the sequence set forth in SEQ ID NO.: 113 and a VL having the sequence set forth in SEQ ID NO.: 168.

Anti-human Fab (CH1-specific) sensors were used to capture antibody at 10 μg/ml for 10 minutes. The IgG-loaded sensors were then exposed to kinetics buffer containing 3 μg/ml of purified human C1q for 4 minutes, followed by a dissociation step in the same buffer for additional 4 minutes. Association and dissociation profiles were measured in real time as changes in the interference pattern. Results are shown in FIG. 54.

Example 32 In Vitro Activation of Human FC Gamma Receptors by Antibodies S309 MLNS, S309 N55Q MLNS, and S309 N55Q MLNS GAALIE

The ability of antibodies S309 MLNS, S309 N55Q MLNS, and S309 N55Q MLNS GAALIE to elicit antibody-dependent activation of human Fcγ receptors was assayed in vitro. S309 MLNS comprises a VH having the sequence set forth in SEQ ID NO.:105 and a VL having the sequence set forth in SEQ ID NO.:168. Each of S309 N55Q MLNS and S309 N55Q MLNS GAALIE comprises a VH having the sequence set forth in SEQ ID NO.: 113 and a VL having the sequence set forth in SEQ ID NO.: 168.

Each of S309 MLNS (also referred to herein as S309 LS), S309 N55Q MLNS (also referred to herein as S309 N55Q LS), S309 N55Q MLNS GAALIE (also referred to herein as S309 N55Q LS GAALIE), and control antibody S309-GRLR was serially diluted 6-fold in assay buffer from 10,000 ng/ml to 0.006 ng/ml. Nine point serial dilutions of antibody were incubated with 12,500 (for FcγRIIIa and FcγRIIb) or 10,000 (for FcγRIIa) CHO-CoV-2-Spike cells per 96-plate well in a white, flat-bottom plate for 15 minutes at room temperature. Jurkat effector cells expressing the indicated FcγRs and stably transfected with an NFAT-driven luciferase gene were thawed, diluted in assay buffer, and added to the plate at an effector to target cell ratio of 6:1 for FcRγIIIa and FcγRIIb or 5:1 for FcγRIIa. Control wells were included to measure antibody-independent activation (containing target cells and effector cells but no antibody) and background luminescence of the plate (wells containing assay buffer only). Plates were incubated for 18 hours at 37° C. with 5% CO₂. Activation of human FcγRs in this bioassay results in the NFAT-mediated expression of the luciferase reporter gene. Luminescence was measured with a luminometer after adding the Bio-Glo™ Luciferase Assay Reagent according to the manufacturer's instructions. Results are shown in FIG. 55.

Example 33 Effector Function of Antibodies S309 MLNS, S309 N55Q MLNS, and S309 N55Q MLNS GAALIE

Antibodies S309 MLNS (also referred to herein as S309 LS), S309 N55Q MLNS (also referred to herein as S309 N55Q LS), and S309 N55Q MLNS GAALIE (also referred to herein as S309 N55Q LS GAALIE) were assayed for their ability to promote NK-cell mediated antibody-dependent cell-mediated cytotoxicity (ADCC) and monocyte-mediated antibody-dependent cellular phagocytosis (ADCP) against cells expressing CoV-2-spike protein.

S309 MLNS comprises a VH having the sequence set forth in SEQ ID NO.:105 and a VL having the sequence set forth in SEQ ID NO.:168. Each of S309 N55Q MLNS and S309 N55Q MLNS GAALIE comprises a VH having the sequence set forth in SEQ ID NO.:113 and a VL having the sequence set forth in SEQ ID NO.:168.

ADCC was measured in vitro by exposing freshly isolated human NK cells from two genotyped donors expressing homozygous low-affinity (F/F158) or high-affinity (V/V158) FcγRIIIa to antibody pre-incubated with CHO-CoV-2-Spike cells and measuring LDH release as a readout according to the manufacturer's instructions (Cytotoxicity Detection Kit (LDH), Roche) after 4 hours of incubation at 37° C. In brief, plates were centrifuged for 4 minutes at 400×g, and 35 μl of supernatant was transferred to a flat 384-well plate. LDH reagent was prepared and 35 μl were added to each well. Using a kinetic protocol, the absorbance at 490 nm and 650 nm was measured once every 2 minutes for 8 minutes, and the slope of the kinetics curve was used as result. The percent specific lysis was determined by applying the following formula: (specific release−spontaneous release)/(maximum release−spontaneous release)×100. Results are shown in FIG. 56.

The ability of antibodies S309 MLNS, S309 N55Q MLNS, S309 N55Q MLNS GAALIE, and control antibody S309-GRLR to promote ADCP by primary CD14+ monocytes was measured in vitro by exposing freshly isolated human PBMCs (labeled with cell trace violet) to CHO-CoV-2-Spike expressing cells (labeled with PKH67 Fluorescent Cell Linker Kit (Sigma Aldrich)) that were pre-incubated with antibody. Serial dilutions of mAbs (serially diluted 5-fold from 5,000 ng/ml to 0.32 ng/ml in RPMI-1640+L-glutamine supplemented with 10% Hyclone FBS+2×anti-anti (antibiotic-antimycotic)) were incubated with 10′000 CHO-CoV-2-Spike cells per well of a 96 well polypropylene plate for 10 minutes. Primary PBMCs were fluorescently labeled with Cell Trace Violet according to the manufacturer's instructions. Target cell and antibody mixtures were then incubated with labeled PBMCs at an effector-to-target ratio of 16:1. ADCP activity was measured after overnight incubation by labeling the monocyte population for CD14, and measuring the percentage of cell trace violet⁺PKH67⁺ cells amongst CD14⁺ monocytes by flow cytometry. Results are shown in FIG. 57.

Example 34 Effect of Antibody S309 on SARS-CoV-2 Spike Protein-Mediated Cell Fusion

The effect of antibody S309 (VH: SEQ ID NO.:105; VL: SEQ ID NO.:168) on SARS-CoV-2 Spike protein-mediated fusion was tested using cells engineered to over-express Spike protein on the cell surface. Adding S309 to these cell cultures inhibited cell-cell fusion. Results are shown in FIG. 58A (micrographs) and 58B (quantified data).

Example 35 Effect of Antibodies S309 N55Q MLNS AND S309 N55Q MLNS GAALIE ON SARS-CoV-2 REPLICATION

The effect of antibodies S309 N55Q MLNS and S309 N55Q MLNS GAALIE on SARS-CoV-2 replication was tested in VeroE6 cells, PBMCs, and dendritic cells. Each of S309 N55Q MLNS and S309 N55Q MLNS GAALIE comprises a VH having the sequence set forth in SEQ ID NO.: 113 and a VL having the sequence set forth in SEQ ID NO.: 168.

SARS-CoV-2 virus was incubated for one hour with S309 N55Q MLNS or S309 N55Q MLNS GAALIE. The virus/antibody mixture was then added to plated VeroE6, PBMC, or monocyte-derived dendritic (MoDC) cells. After incubating the cells with the virus/antibody mixture for one hour at 37° C., the cells were washed and incubated for a further 72 hours in fresh medium. The supernatant from the cultured cells was then assayed for focus-forming units (FFU). The supernatant was diluted 1:5 and added to VeroE6 cells. After one hour at 37° C., the VeroE6 cells were overlaid with methylcellulose. After 24 hours' further incubation, the VeroE6 cell cultures were stained for SARS-CoV-2 nucleoprotein. Results are shown in FIG. 59. Data for antibody S309 N55Q MLNS is shown in the top panel. Data for antibody S309 N55Q MLNS GAALIE is shown in the bottom panel. These 72-hour replication data are representative of findings at 24 and 48 hours.

Example 36 Materials and Methods

Flow-Cytometry Based Screening for Binding to CoV S Protein Expressed on Mammalian Cells

ExpiCHO cells were transfected with S protein of SARS-CoV-2, SARS-CoV and MERS-CoV, or with an empty plasmid as a negative control. The monoclonal antibodies were then tested by flow-cytometry at 10 μg/ml for their ability to stain ExpiCHO cells expressing the S protein of 2019-nCoV, SARS-CoV, MERS-CoV or Mock cell transfectants.

Transient Expression of Recombinant SARS-CoV-2 Protein

The full-length S gene of SARS-CoV-2 strain (2019-nCoV-S) isolate BetaCoV/Wuhan-Hu-1/2019 (accession number MN908947) was codon optimized for human cell expression and cloned into the phCMV1 expression vector (Genlantis). Expi-CHO cells were transiently transfected with phCMV1-SARS-CoV-2-S, phCMV1-MERS-CoV-S (London1/2012), SARS-spike_pcDNA.3 (strain SARS) or the empty phCMV1 (Mock) using Expifectamine CHO Enhancer. Two days after transfection, cells were collected, fixed, or fixed and permeabilized with saponin for immunostaining with a panel of monoclonal antibodies reactive to SARS-CoV Receptor Binding Domain (RBD). An Alexa647-labelled secondary antibody anti-human IgG Fc was used for detection. Binding of antibodies to transfected cells was analyzed by flow-cytometry using a ZE5 Cell Analyzer (Biorard) and FlowJo software (TreeStar). Positive binding was defined by differential staining of CoV-S-transfectants versus mock-transfectants.

Competition Experiments Using Octet (BLI, Biolayer Interferometry)

Unless otherwise indicated herein, anti-His sensors (BIOSENSOR ANTI-PENTA-HIS (HIS1K)) were used to immobilize the Si subunit protein of SARS-CoV (Sino Biological Europe GmbH). Sensors were hydrated for 10 min with Kinetics Buffer (KB; 0.01% endotoxin-free BSA, 0.002{circumflex over ( )} Tween-20, 0.005% NaN3 in PBS). SARS-CoV 51 subunit protein was then loaded for 8 min at a concentration of 10 μg/ml in KB. Antibodies were associated for 6 min at 15 μg/ml for full length mAbs nCoV-10 and nCov-6 mAbs or 5 μg/ml for Fab nCoV-4, and in a subsequent experiment comprising nCoV-1 all at 10 μg/ml. Competing antibodies were then associated at the same concentration for additional 6 mins.

Competition Experiments Using Octet (BLI, Biolayer Interferometry)

For ACE2 competition experiments, ACE2-His (Bio-Techne AG) was loaded for 30 minutes at 5 μg/ml in KB onto anti-HIS (HIS2) biosensors (Molecular Devices-ForteBio). SARS-CoV-1 RBD-rabbitFc or SARS-CoV-2 RBD-mouseFc (Sino Biological Europe GmbH) at 1 μg/ml was associated for 15 minutes, after a preincubation with or without antibody (30 μg/ml, 30 minutes). Dissociation was monitored for 5 minutes.

Affinity Determination Using Octet (BLI, Biolayer Interferometry)

For K_(D) determination of full-length antibodies, protein A biosensors (Pall ForteBio) were used to immobilize recombinant antibodies at 2.7 μg/ml for 1 minute, after a hydration step for 10 minutes with Kinetics Buffer. Association curves were recorded for 5 min by incubating the antibody-coated sensors with different concentration of SARS-CoV-1 RBD (Sino Biological) or SARS-CoV-2 RBD (produced in house; residues 331-550 of spike from BetaCoV/Wuhan-Hu-1/2019, accession number MN908947). Highest RBD concentration tested was 10 ug/ml, then 1:2.5 serially diluted. Dissociation was recorded for 9 min by moving the sensors to wells containing KB. K_(D) values were calculated using a global fit model (Octet). Octet Red96 (ForteBio) equipment was used.

For K_(D) determination of full-length antibodies compared to Fab fragments, His-tagged RBD of SARS-CoV-1 or SARS-CoV-2 were loaded at 3 μg/ml in KB for 15 minutes onto anti-HIS (HIS2) biosensors (Molecular Devices, ForteBio). Association of full-length antibody and Fab was performed in KB at 15 ug/ml and 5 ug/ml respectively for 5 minutes. Dissociation in KB was measured for 10 min.

ELISA Binding

The reactivities of mAbs with SARS-CoV Spike Si Subunit Protein (strain WH20) protein were determined by enzyme-linked immunosorbent assays (ELISA). Briefly, 96-well plates were coated with 3 μg/ml of recombinant SARS-CoV Spike Si Subunit Protein (Sino. Biological). Wells were washed and blocked with PBS+1% BSA for 1 h at room temperature and were then incubated with serially diluted mAbs for 1 h at room temperature. Bound mAbs were detected by incubating alkaline phosphatase-conjugated goat anti-human IgG (Southern Biotechnology: 2040-04) for 1 h at room temperature and were developed by 1 mg/ml p-nitrophenylphosphate substrate in 0.1 M glycine buffer (pH 10.4) for 30 min at room temperature. The optical density (OD) values were measured at a wavelength of 405 nm in an ELISA reader (Powerwave 340/96 spectrophotometer, BioTek).

Neutralization Assay

Unless otherwise indicated, Murine leukemia virus (MLV) pseudotyped with SARS-CoV-2 Spike protein (SARS-CoV-2pp) or SARS-CoV-1 Spike protein (SARS-CoV-1pp) were used. DBT cells stably transfected with ACE2 (DBT-ACE2) were used as target cells. SARS-CoV-2pp or SARS-CoV-1pp was activated with trypsin TPCK at 10 ug/ml. Activated SARS-CoV-2pp or SARS-CoV-1pp was added to a dilution series of antibodies (starting 50 ug/ml final concentration per antibody, 3-fold dilution). DBT-ACE2 cells were added to the antibody-virus mixtures and incubated for 48h. Luminescence was measured after aspirating cell culture supernatant and adding steady-GLO substrate (Promega).

Unless otherwise indicated, pseudoparticle neutralization assays use a VSV-based luciferase reporter pseudotyping system (Kerafast). VSV pseudoparticles and antibody are mixed in DMEM and allowed to incubate for 30 minutes at 37 C. The infection mixture is then allowed to incubate with Vero E6 cells for 1h at 37 C, followed by the addition of DMEM with Pen-Strep and 10% FBS (infection mixture is not removed). The cells are incubated at 37 C for 18-24 hours. Luciferase is measured using an Ensight Plate Reader (Perkin Elmer) after the addition of Bio-Glo reagent (Promega).

SPR Single-Cycle Kinetics

SPR experiments were carried out with a Biacore T200 instrument using a single-cycle kinetics approach. S309 IgG was captured on the surface and increasing concentrations of purified SARS-CoV-2 RBD, either glycosylated or deglycosylated, were injected. Association and dissociation kinetics were monitored and fit to a binding model to determine affinity.

Expression of Recombinant Antibodies

Recombinant antibodies were expressed in ExpiCHO cells transiently co-transfected with plasmids expressing the heavy and light chain as previously described. (Stettler et al. (2016) Specificity, cross-reactivity, and function of antibodies elicited by Zika virus infection. Science, 353(6301), 823-826) Monoclonal antibodies S303, S304, S306, S309, S310, and S315 were expressed as rIgG-MLNS antibodies. The MLNS mutation confers a longer half-life in vivo. (Zalevsky et al. (2010) Enhanced antibody half-life improves in vivo activity. Nature Biotechnology, 28(2), 157-159)

Sequence Alignment

SARS-CoV-2 genomics sequences were downloaded from GISAID on Mar. 29 2020, using the “complete (>29,000 bp)” and “low coverage exclusion” filters.

Bat and pangolin sequences were removed to yield human-only sequences. The spike ORF was localized by performing reference protein (YP_009724390.1)-genome alignments with GeneWise2. Incomplete matches and indel-containing ORFs were rescued and included in downstream analysis. Nucleotide sequences were translated in silico using seqkit. Sequences with more than 10% undetermined aminoacids (due to N basecalls) were removed. Multiple sequence alignment was performed using MAFFT. Variants were determined by comparison of aligned sequences (n=2,229) to the reference sequence using the R/Bioconductor package Biostrings. A similar strategy was used to extract and translate spike protein sequences from SARS-CoV genomes sourced from ViPR (search criteria: SARS-related coronavirus, full-length genomes, human host, deposited before December 2019 to exclude SARS-CoV-2, n=53). Sourced SARS-CoV genome sequences comprised all the major published strains, such as Urbani, Tor2, TW1, P2, Frankfurtl, among others. Pangolin sequences as shown by Tsan-Yuk Lam et al were sourced from GISAID. Bat sequences from the three clades of Sarbecoviruses as shown by Lu et al (Lancet 2020) were sourced from Genbank. Civet and racoon dog sequences were similarly sourced from Genbank.

Example 37 ACE2-Independent Mechanism of SARS-CoV2 Neutralization by S309 Antibody

In the following experiments, S309 antibody (VH of SEQ ID NO.:105, VL of SEQ ID NO.:168) was expressed as recombinant IgG1 with M428L and N434S Fc mutations. The effect of ACE2 overexpression on S309 antibody neutralization of infection was investigated. Vero E6 or Vero E6-TMPRSS2 cells were infected with SARS-CoV-2 (isolate USA-WA1/2020) at MOI 0.01 in the presence of S309 (10 μg/ml). Cells were fixed 24h post infection, viral nucleocapsid protein was immunostained and quantified. Nucleocapsid staining was effectively absent in antibody-treated cells. S309 had an IC50 (ng/mL) in Vero E6 cells of 65 and in Vero E6-TMPRSS2 of 91 (data not shown).

A panel of 7 cell lines (HeLa, 293T (wt), Vero E6, Huh7, 293T ACE2, MRC 5-ACE2-TMPRSS2, A549-ACE2-TMPRSS2 clone 5, A549-ACE2-TMPRSS2 clone 10) were infected with SARS-CoV-2-Nluc or VSV pseudotyped with the SARS-CoV-2 spike protein in the presence of S309. Luciferase signal was quantified 24h post infection. S309 maximum neutralization values were as shown in Table 12.

TABLE 12 Maximum Neutralization Values of S309 Virus/Pseudotype Cell Type SARS-CoV-2-Nluc VSV Pseudotype Vero E6 >99%   >99%   Vero E6-TMPRSS2 >99%   96% Huh7 98% 78% 293T ACE2 26% 34% MRC5-ACE2-TMPRSS2 87% 45% A549-ACE2-TMPRSS2 clone 5 89% 65% A549-ACE2-T1V1PRSS2 clone 10 81% 42%

Binding of purified, fluorescently-labeled SARS-CoV-2 spike protein binding to these cell lines was quantified by flow cytometry. HeLa and 239T WT cells had he lowest MFIs, followed by Huh7 and VeroE6 cells. 293T ACE2 cells (highest), MRC 5-ACE2-TMPRSS2 (third-highest), A549-ACE2-TMPRSS2 clone 5 (fourth-highest), and A549-ACE2-TMPRSS2 clone 10 (second-highest) had higher MFIs. Correlation analysis between spike binding maximum neutralization potential of S309 was determined; S309 Spearman correlation values were: r=−0.94 for both viral models. p=0.017.

To further characterize SARS-CoV-2-susceptible cell lines, the seven cell lines described above were incubated with purified, fluorescently-labeled SARS-CoV-2 spike protein or RBD protein and protein binding was quantified by flow cytometry. In descending order of MFI, the cell lines were: A549-ACE2-TMPRSS2 clone 10; 293T ACE2; MRC 5-ACE2-TMPRSS2; A549-ACE2-TMPRSS2 clone 5; Vero E6; Huh7; 293T (wt); and HeLa.

Selected lectins and published receptor candidates were screened using HEK293T cells infected with SARS-CoV-2 VSV pseudoviruses. ACE2, DC-SIGN, L-SIGN, and SIGLEC-1 gave the highest signals. ACE2 provided a signal of approximately 10⁵ relative luminescence units (RLUs), and DC-SIGN, SIGLEC-1, and L-SIGN had signals of approximately 10⁴ RLUs. All other lectins/candidates tested gave signals of approximately 10²-10³ RLUs.

HEK 293T, HeLa and MRCS cells were transiently transduced to overexpress DC-SIGN, L-SIGN, SIGLEC1 or ACE2 and infected with SARS-CoV-2 VSV pseudoviruses. Uninfected cells and untransduced cells were included as controls. In HEK293T cells, ACE2, DC-SIGN, SIGLEC-1, and L-SIGN all provided substantial increases in infection. In HeLa and MRCS cells, only ACE2 increased infection.

Stable HEK293T cell lines overexpressing DC-SIGN, L-SIGN, SIGLEC-1 or ACE2 were infected with authentic SARS-CoV-2 (MOI 0.1), fixed and immunostained at 24 hours for the SARS-CoV-2 nucleoprotein. Wild-type cells (infected and uninfected) were used as controls. Increased staining was observed in cells overexpressing DC-SIGN, L-SIGN, or SIGLEC-1, and staining was significantly increased in cells overexpressing ACE2.

Stable cell lines were infected with SARS-CoV-2-Nluc and luciferase levels were quantified at 24 hours. In ascending order of RLUs: uninfected (approx. 10²-10³ RLUs); parental 293T (approx. 10⁴ RLUs); DC-SIGN (approx. 10⁵ RLUs); L-SIGN (approx. 10⁵ RLUs); SIGLEC-1 (approx. 10⁵-10⁶RLUs); ACE2 (>10⁷ RLUs).

Stable cell lines were incubated with different concentration of anti-SIGLEC1 mAb (clone 7-239) and infected with SARS-CoV-2-Nluc. Infection as a percentage of untreated cells remained near to exceeded 100% in 293T cells expressing DC-SIGN, L-SIGN, or ACE2, but dropped to below 50% (0.2 μg/mL anti-SIGLEC) to close to 0 (1 μg/mL or 5 μg/mL anti-SIGLEC) in 293T cells expressing SIGLEC-1.

Single cell expression levels of selected potential SARS-CoV-2 (co)receptor candidates were determined in different lung cell types derived from the Human Lung Cell Atlas (nature.com/articles/s41586-020-2922-4). DC-SIGN, L-SIGN and SIGLEC-1 are expressed in a variety of cell types in the lung at levels similar to or even higher than ACE2.

Binding of antibodies targeting DC-/L-SIGN, DC-SIGN, SIGLEC1 or ACE2 on HEK293T cells stably over-expressing the respective attachment receptor was analyzed by flow cytometry and immunofluorescence analysis. HEK 293T cells over-expressing the respective attachment receptors were infected with VSV pseudotyped with SARS-COV-2 wildtype spike or spike bearing mutations of the B1.1.7 lineage. Luminescence was analyzed one day post infection. Infection was increased in cells expressing the attachment receptors. Infection by VSV pseudotyped with either spike was similar for each test group. Cells expressing ACE2 gave the highest luminescence signal.

Vero E6 cells, in vitro differentiated moDCs or PBMCs were infected with SARS-CoV-2 at MOI 0.01. At 24h post infection, cells were fixed, immunostained for viral nucleocapsid protein and infected cells were quantified. Only VeroE6 cells showed infection (approximately 7% of cells). Supernatant of the infected cells was taken at 24, 48 and 72h and infectious viral titer was quantified by FFU assay on Vero E6 cells.

Major cell types with detectable SARS-CoV-2 genome in bronchoalveolar lavage fluid (BALF) and sputum of severe COVID-19 patients were assessed. A t-SNE plot was generated, and the count of each SARS-CoV-2+ cell type was determined (total n=3,085 cells from 8 subjects in Ren et al. Cell 2021). Cell types were T, NK, plasma, neutrophil, macrophage, ciliated, squamous, and secretory. Expression of ACE2, DC-SIGN, L-SIGN, SIGLEC-1, and combinations of these was assessed for each cell type.

ACE2, DC-SIGN (CD209), L-SIGN (CLEC4M), SIGLEC1 transcript counts were correlated with SARS-CoV-2 RNA counts in macrophages and in secretory cells. Correlation was based on counts (before log transformation), from Ren et al. Cell 2021.

Representative data showing expression of receptors in stable HEK293T cell lines are shown in FIG. 60. Cell lines were generated to overexpress DC-SIGN, L-SIGN or ACE2 by transducing HEK293T cells with lentivirus encoding the transgene, and immunofluorescence assays were performed to assess transgene expression.

Representative data showing the ability of VSV pseudovirus expressing SARS-CoV-2 S protein with luciferase reporter to infect the HEK293T cells (using a luminescence assay) are shown in FIG. 61; expression of DC-SIGN or L-SIGN increased pseudovirus infection levels by over 10-fold compared to infection of WT HEK293T cells, and expression of ACE2 increased pseudovirus infection levels by over 100-fold compared to infection of WT HEK293T cells.

Neutralizing activity of exemplary mAb S309 against the VSV pseudovirus was assessed in the engineered HEK293T cells. Data are shown in FIG. 62; S309 fully neutralized infection via DC-SIGN and L-SIGN, and to a lesser extent, ACE2.

The ability of live SARS-CoV-2 with luciferase reporter to infect the HEK293T cells was examined using a luminescence assay. Data are shown in FIG. 63; expression of DC-SIGN or L-SIGN increased live virus infection levels by over 3-fold compared to infection of WT HEK293T cells, and expression of ACE2 increased live virus infection levels by over 100-fold compared to infection of WT HEK293T cells.

Neutralizing activity of mAb S309 against the VSV pseudovirus was assessed in the engineered HEK293T cells. Data are shown in FIG. 64; S309 fully neutralized infection via DC-SIGN and L-SIGN, and neutralized infection via ACE2 to a lesser extent.

Experiments were performed to investigate whether S309 antibody can neutralize entry of SARS-CoV-2 via SIGLEC-1. Briefly, stable cell HEK293T lines were generated as described above to overexpress DC-SIGN/L-SIGN, DC-SIGN, SIGLEC-1, or ACE2. Expression data are shown in FIG. 65. As shown in FIG. 66, expression of DC-SIGN, L-SIGN, or SIGLEC increased live virus infection levels by over 10-fold compared to infection of WT HEK293T cells, and expression of ACE2 increased pseudovirus infection levels by over 100-fold compared to infection of WT HEK293T cells. As shown in FIG. 67, S309 fully neutralized infection via DC-SIGN, L-SIGN, and SIGLEC-1.

Expression of DC-SIGN (CD209) and other cell surface receptor proteins including SIGLEC-1 and other SIGLECs was determined on a variety of cell types. Data are summarized in FIGS. 68A and 68B.

Further experiments were performed to investigate the function(s) of DC-SIGN, L-SIGN, and SIGLEC-1 in SARS-CoV-2 infection. In one set of experiments, HEK293T cells stably expressing DC-SIGN, L-SIGN, SIGLEC-1 or ACE2 were infected with live SARS-CoV-2 Nluc at three different multiplicities of infection (MOI): 0.01, 0.1, and 1). Infection was determined using relative luminescence units and compared to infection in HEK293T cells (parental). Data are shown in FIG. 69. At the lowest MOI tested, an increase of infection in cells expressing DC-SIGN, L-SIGN, or SIGLEC was observed. At the highest MOI tested, infection was not further increased versus parental by expression of DC-SIGN, L-SIGN, or SIGLEC. These data indicate that the parental 293T cells are susceptible to infection by SARS-CoV-2 and L-SIGN, DC-SIGN, and SIGLEC-1 enhance infection levels but do not function as primary receptors for infection.

In another set of experiments, 293T cells, HeLa cells, and MRCS cells were transiently transduced with lentivirus encoding DC-SIGN, L-SIGN, SIGLEC-1 or ACE2 and infected with VSV pseudovirus three days after transduction. Data are shown in FIG. 70. While the 293T cells showed a low level of susceptibility (compare uninfected with untransduced), HeLa and MRCS cells were completely refractory to the virus. The low level of infection in 293T cells can be increased by expression of L-SIGN, DC-SIGN, or SIGLEC-1, consistent with a role for these proteins as as attachment factors. The HeLa and MRCS cells remained refractory to infection even after expression of L-SIGN, DC-SIGN, or SIGLEC-1, and only become susceptible after expression of ACE2. These data indicate that L-SIGN, DC-SIGN, and SIGLEC-1 are not primary receptors for SARS-CoV-2.

Example 38 In Vivo Efficacy of S309 Antibody

The efficacy of S309 was investigated in Syrian hamsters. This animal model represents to-date the most relevant model of SARS-CoV-2 infection that did not require in vivo over-expression of ACE2 to support productive infection and disease. Prophylactic administration of S309 induced dose-dependent protection against SARS-CoV-2 infection and tissue damage in hamsters, as demonstrated by the viral RNA levels, the viral load as well as the histopathological score in the lungs (FIGS. 73A-7C). These data indicate that poor and incomplete neutralization of entry by S309 in vitro when using ACE2 over-expressing cells did not compromise in vivo efficacy of non-RBM mAbs.

S309 carrying the N297A mutation has a reduced capacity to trigger effector functions as a consequence of diminished engagement to Fcγ receptors. This was further confirmed by the reduced binding of S309-N297A variant to hamster monocytes in the spleen. The in vivo efficacy measured with the N297A mAb is similar or just slightly inferior to the wt S309, suggesting that neutralizing capacity of the mAb is prevailing upon its effector function capacity in these conditions. The serum concentration of S309 required to reduce the viral RNA in the lung by 90% was 9 μg/ml, FIG. 73D.

Example 39 Antibody Activity Against SARS-CoV-2 Variants

A number of SARS-CoV-2 variants have emerged, with increasing numbers of infection by variants reported in late 2020. The Receptor Binding Motif (RBM) appears to be particularly variable to mutation. Notable emerging variants have been observed in Scotland, the UK, South Africa, California, Columbus, and in minks in Denmark, and some mutations have been reported to confer escape from antibodies or serum neutralization. Experiments were performed to assess the ability of S309 antibodies to neutralize variants. S309 N55Q MLNS (VH: SEQ ID NO.:113; VL: SEQ ID NO.:168; with M428L and N434S Fc mutations) was tested against SARS-CoV-2 bearing a panel of the 20 most-frequent SARS-CoV-2 RBD variant mutations, as determined by sequence reads. Antibodies REGN10933 and REGN10987 (Hansen et al., Science 369(6506):1010-1014; eabd0827-0810 (2020) and PDB 6XDG (rcsb.org/structure/6XDG)) were included for comparison. Results are summarized in Table 13.

Y=less than three-fold decrease in neutralizing of live virus or pseudovirus;

N=greater than three-fold decrease in neutralizing of live virus or pseudovirus;

P=neutralization by antibody is predicted due to variant amino acid being outside of epitope; ?=unknown.

TABLE 13 Summary of Neutralization by Antibodies Against SARS CoV-2 Variants S309 N55Q Variant Mutation MLNS REGN10933 REGN10987 N501Y (UK, South African, Y Y Y and Brazilian mutant) S477N Y Y Y N439K (Scottish mutant) Y Y N L452R (Californian mutant) Y P P E484K (South African and Y N Y Brazilian mutant) Y453F (mink mutant) Y N N (4x decrease) A520S Y Y Y K417N (South African Y N Y mutant) (K417N/V) (K417N/E/V) 5494P Y N P 5477R P ? P V367F Y Y Y P384L Y P P A5225 Y P P A522V Y P P V382L Y P P N501T Y P P P330S Y P P T4781 Y ? P S4771 Y ? P P4795 Y P P Y = less than three-fold decrease in neutralizing of live virus or pseudovirus N = greater than three-fold decrease in neutralizing of live virus or pseudovirus P = neutralization by antibody is predicted due to variant amino acid being outside of epitope ? = unknown.

Total counts of SARS-CoV-2 sequenced mutants known to escape the antibodies (as of Jan. 29, 2021) were: S309 N55Q MLNS=29; REGN10987=10,425; REGN10933=3,621.

Binding of S309 antibodies to SARS-CoV-2 variant RBDs was assessed by BLI. S309 (VH: SEQ ID NO.:105; VL: SEQ ID NO.:168) with wild-type Fc and S309 N55Q (VH: SEQ ID NO.:113; VL: SEQ ID NO.:168) bearing MLNS or MLNS+GAALIE Fc mutations were assessed. REGN10987 and REGN10933 were included as comparators. Briefly, antibodies were diluted in kinetics buffer at 3 ug/ml and loaded on Protein-A sensors for 75 seconds. After a short equilibration step in kinetics buffer, loaded sensors were moved in wells containing the RBD variants at 5 ug/ml in kinetics buffer and association was recorded during 3 minutes. Dissociation of the complex was performed in kinetics buffer for 3 minutes. Data are shown in FIGS. 71A-71B; “WT”=Wuhan-Hu-1 with D614G; “Triple Mutant” in lower row=Wuhan-Hu-1 with D614G and added South Africa variant B.1.351 RBD mutations K417N, E484K, and N501Y. Other mutations present in the South Africa variant B.1.351 were not present in the “SA” RBD tested.

Neutralization of S309 antibodies against SARS-CoV-2 variants was assessed using MLV pseudovirus and Vero-E6 target cells expressing TMPRSS2. S309 (VH: SEQ ID NO.:105; VL: SEQ ID NO.:168) with wild-type Fc and S309 N55Q (VH: SEQ ID NO.:113; VL: SEQ ID NO.:168) bearing MLNS or MLNS+GAALIE Fc mutations were assessed. REGN10987, REGN10933, and the combination of REGN10987+REGN10933, were also assessed. Data are shown in FIG. 72. “WT”=Wuhan-Hu-1; “UK”=SARS-CoV-2 variant B.1.1.7; and “SA”=variant B.1.351.

The various embodiments described above can be combined to provide further embodiments. All of the U.S. patents, U.S. patent application publications, U.S. patent applications, foreign patents, foreign patent applications and non-patent publications referred to in this specification and/or listed in the Application Data Sheet, including U.S. Patent Application No. 62/981,984, filed on Feb. 26, 2020, U.S. Patent Application No. 62/982,661, filed on Feb. 27, 2020, U.S. Patent Application No. 62/987,298, filed on Mar. 9, 2020, U.S. Patent Application No. 62/989,522, filed on Mar. 13, 2020, U.S. Patent Application No. 62/990,369, filed on Mar. 16, 2020, U.S. Patent Application No. 62/992,082, filed on Mar. 19, 2020, U.S. Patent Application No. 62/994,235, filed on Mar. 24, 2020, U.S. Patent Application No. 63/001,204, filed on Mar. 27, 2020, U.S. Patent Application No. 63/003,214, filed on Mar. 31, 2020, U.S. Patent Application No. 63/005,206, filed on Apr. 3, 2020, U.S. Patent Application No. 63/010,589, filed on Apr. 15, 2020, U.S. Patent Application No. 63/011,971, filed on Apr. 17, 2020, U.S. Patent Application No. 63/014,024, filed on Apr. 22, 2020, U.S. Patent Application No. 63/023,788, filed on May 12, 2020, U.S. Patent Application No. 63/025,133, filed on May 14, 2020, U.S. Patent Application No. 63/039,813, filed on Jun. 16, 2020, U.S. Patent Application No. 63/043,653, filed on Jun. 24, 2020, U.S. Patent Application No. 63/050,331, filed on Jul. 10, 2020, and U.S. Patent Application No. 63/052,810, filed on Jul. 16, 2020, are incorporated herein by reference, in their entirety. Aspects of the embodiments can be modified, if necessary to employ concepts of the various patents, applications and publications to provide yet further embodiments.

These and other changes can be made to the embodiments in light of the above-detailed description. In general, in the following claims, the terms used should not be construed to limit the claims to the specific embodiments disclosed in the specification and the claims, but should be construed to include all possible embodiments along with the full scope of equivalents to which such claims are entitled. Accordingly, the claims are not limited by the disclosure. 

What is claimed is:
 1. An isolated antibody, or an antigen-binding fragment thereof, comprising a heavy chain variable domain (VH) that comprises the complementarity determining region (CDR)H1 amino acid sequence set forth in SEQ ID NO.:106, the CDRH2 amino acid sequence set forth in SEQ ID NO.:121, and the CDRH3 amino acid sequence set forth in SEQ ID NO.:108, and a light chain variable domain (VL) that comprises the CDRL1 amino acid sequence set forth in SEQ ID NO.:169, the CDRL2 amino acid sequence set forth in SEQ ID NO.:170, and the CDRL3 amino acid sequence set forth in SEQ ID NO.:171, wherein the antibody or antigen-binding fragment is capable of binding to a SARS-CoV-2 surface glycoprotein (S): expressed on a cell surface of a host cell; on a SARS-CoV-2 virion; or both.
 2. The isolated antibody or antigen-binding fragment of claim 1, which is capable of binding to a surface glycoprotein (S) of: (i) a SARS-CoV-2 Wuhan-Hu-1 (SEQ ID NO.:165); (ii) a SARS-CoV-2 B.1.1.7; (iii) a SARS-CoV-2 B.1.351; (iv) a SARS-CoV-2 comprising any one or more of the following substitution mutations relative to SEQ ID NO.:165: N501Y; S477N; N439K; L452R; E484K; Y453F; A520S; K417N; K417V; S494P; N501T; 5477R; V367F; P384L; A522S; A522V; V382L; P330S; T478I; S477I; P479S; or (v) any combination of (i)-(iv).
 3. The isolated antibody or antigen-binding fragment of claim 1, which is capable of neutralizing a SARS-CoV-2 infection: (i) in an in vitro model of infection; (ii) in an in vivo animal model of infection; (iii) in a human; or (iv) any combination of (i)-(iii).
 4. The isolated antibody or antigen-binding fragment of claim 1, wherein: (i) the VH comprises or consists of an amino acid sequence having at least 85% identity to the amino acid sequence set forth in SEQ ID NO.:113; and/or (ii) the VL comprises or consists of an amino acid sequence having at least 85% identity to the amino acid sequence set forth in SEQ ID NO.:168.
 5. The isolated antibody or antigen-binding fragment of claim 4, wherein: (i) the VH comprises or consists of an amino acid sequence having at least 90% identity to the amino acid sequence set forth in SEQ ID NO.:113; and/or (ii) the VL comprises or consists of an amino acid sequence having at least 90% identity to the amino acid sequence set forth in SEQ ID NO.:168.
 6. The isolated antibody or antigen-binding fragment of claim 4, wherein: (i) the VH comprises or consists of an amino acid sequence having at least 95% identity to the amino acid sequence set forth in SEQ ID NO.:113; and/or (ii) the VL comprises or consists of an amino acid sequence having at least 95% identity to the amino acid sequence set forth in SEQ ID NO.:168.
 7. The isolated antibody or antigen-binding fragment of claim 4, wherein: (i) the VH comprises or consists of an amino acid sequence having at least 99% identity to the amino acid sequence set forth in SEQ ID NO.:113; and/or (ii) the VL comprises or consists of an amino acid sequence having at east 99% identity to the amino acid sequence set forth in SEQ ID NO.:168.
 8. The isolated antibody or antigen-binding fragment of claim 1, which is capable of inhibiting an interaction between: (i) SARS-CoV-2 and a human DC-SIGN; (ii) SARS-CoV-2 and a human L-SIGN; (iii) SARS-CoV-2 and a human SIGLEC-1; or (iv) any combination of (i)-(iii).
 9. The isolated antibody or antigen-binding fragment of claim 1, wherein the antibody or antigen-binding fragment comprises a human antibody, a monoclonal antibody, a purified antibody, a single chain antibody, a Fab, a Fab′, a F(ab′)2, a Fv, a scFv, or a scFab.
 10. The isolated antibody or antigen-binding fragment of claim 1, wherein the antibody or antigen-binding fragment further comprises a Fc polypeptide or a fragment thereof.
 11. The isolated antibody or antigen-binding fragment of claim 10, wherein the Fc polypeptide or fragment thereof comprises: (i) a mutation that enhances binding to a FcRn as compared to a reference Fc polypeptide that does not comprise the mutation; and/or (ii) a mutation that enhances binding to a FcγR as compared to a reference Fc polypeptide that does not comprise the mutation.
 12. The isolated antibody or antigen-binding fragment of claim 11, wherein the mutation that enhances binding to a FcRn comprises: (i) M428L/N434S; (ii) M252Y/S254T/T256E; (iii) T250Q/M428L; (iv) P257I/Q311I; (v) P257I/N434H; (vi) D376V/N434H; (vii) T307A/E380A/N434A; or (viii) any combination of (i)-(vii).
 13. The isolated antibody or antigen-binding fragment of claim 12, wherein the mutation that enhances binding to FcRn comprises M428L/N434S.
 14. The isolated antibody or antigen-binding fragment of claim 12, wherein the mutation that enhances binding to a FcγR comprises S239D, I332E, A330L, G236A, or any combination thereof.
 15. The isolated antibody or antigen-binding fragment of claim 14, wherein the mutation that enhances binding to a FcγR comprises: (i) S239D/I332E; (ii) S239D/A330L/I332E; (iii) G236A/S239D/I332E; or (iv) G236A/A330L/I332E.
 16. The isolated antibody or antigen-binding fragment of claim 1, which is a IgG, IgA, IgM, IgE, or IgD isotype.
 17. The isolated antibody or antigen-binding fragment of claim 1, further comprising a CH1-CH3 that comprises or consists of the amino acid sequence set forth in SEQ ID NO.:265 or
 266. 18. An isolated antibody, or an antigen-binding fragment thereof, comprising a heavy chain variable domain (VH) and a light chain variable domain (VL), wherein the VH comprises or consists of the amino acid sequence set forth in SEQ ID NO.:113 and the VL comprises or consists of the amino acid sequence set forth in SEQ ID NO.:168.
 19. The isolated antibody or antigen-binding fragment of claim 18, which is capable of neutralizing a SARS-CoV-2 infection: (i) in an in vitro model of infection; (ii) in an in vivo animal model of infection; (iii) in a human; or (iv) any combination of (i)-(iii).
 20. The isolated antibody or antigen-binding fragment of claim 18, which is capable of inhibiting an interaction between: (i) SARS-CoV-2 and a human DC-SIGN; (ii) SARS-CoV-2 and a human L-SIGN; (iii) SARS-CoV-2 and a human SIGLEC-1; or (iv) any combination of (i)-(iii).
 21. The isolated antibody or antigen-binding fragment of claim 18, wherein the antibody or antigen-binding fragment further comprises a Fc polypeptide or a fragment thereof.
 22. The isolated antibody or antigen-binding fragment of claim 21, which is a IgG, IgA, IgM, IgE, or IgD isotype.
 23. The isolated antibody or antigen-binding fragment of claim 21, wherein the Fc polypeptide or fragment thereof comprises: (i) a mutation that enhances binding to a FcRn as compared to a reference Fc polypeptide that does not comprise the mutation; and/or (ii) a mutation that enhances binding to a FcγR as compared to a reference Fc polypeptide that does not comprise the mutation.
 24. The isolated antibody or antigen-binding fragment of claim 23, wherein the mutation that enhances binding to a FcRn comprises: (i) M428L/N434S; (ii) M252Y/S254T/T256E; (iii) T250Q/M428L; (iv) P257I/Q311I; (v) P257I/N434H; (vi) D376V/N434H; (vii) T307A/E380A/N434A; or (viii) any combination of (i)-(vii).
 25. The isolated antibody or antigen-binding fragment of claim 24, wherein the mutation that enhances binding to FcRn comprises M428L/N434S.
 26. The isolated antibody or antigen-binding fragment of claim 23, wherein the mutation that enhances binding to a FcγR comprises S239D, I332E, A330L, G236A, or any combination thereof.
 27. The isolated antibody or antigen-binding fragment of claim 26, wherein the mutation that enhances binding to a FcγR comprises: (i) S239D/I332E; (ii) S239D/A330L/I332E; (iii) G236A/S239D/I332E; or (iv) G236A/A330L/I332E.
 28. The isolated antibody or antigen-binding fragment of claim 18, further comprising a CH1-CH3 that comprises or consists of the amino acid sequence set forth in SEQ ID NO.:265 or
 266. 29. An isolated antibody that comprises: (i) a heavy chain comprising (i)(1) a VH that comprises or consists of the amino acid sequence set forth in SEQ ID NO.:113, and (i)(2) a CH1-CH3 that comprises or consists of the amino acid sequence set forth in SEQ ID NO.:173; and (ii) a light chain comprising (ii)(1) a VL that comprises or consists of the amino acid sequence set forth in SEQ ID NO.: 168, and (ii)(2) a CL that comprises or consists of the amino acid sequence set forth in SEQ ID NO.:174.
 30. An isolated antibody that comprises: (i) a heavy chain comprising (i)(1) a VH that comprises or consists of the amino acid sequence set forth in SEQ ID NO.:113, and (i)(2) a CH1-CH3 that comprises or consists of the amino acid sequence set forth in SEQ ID NO.:175; and (ii) a light chain comprising (ii)(1) a VL that comprises or consists of the amino acid sequence set forth in SEQ ID NO.: 168, and (ii)(2) a CL that comprises or consists of the amino acid sequence set forth in SEQ ID NO.:174. 